Agricultural systems

ABSTRACT

An agricultural implement includes at least one row unit having a plurality of support members, each of which is pivotably coupled to an attachment frame or another of the support members to permit vertical pivoting vertical movement of the support members, and a plurality of soil-engaging tools, each of which is coupled to at least one of the support members. A plurality of hydraulic cylinders are coupled to the support members for urging the support members downwardly toward the soil. A plurality of controllable pressure control valves are coupled to the hydraulic cylinders for controlling the pressure of hydraulic fluid supplied to the cylinders. A plurality of sensors produce electrical signals corresponding to predetermined conditions, and a controller is coupled to the sensor and the controllable pressure control valves. The controller receives the electrical signals from the sensors and produces control signals for controlling the pressure control valves.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part and claims priority to

-   -   (1) U.S. Provisional Application No. 61/798,266, filed Mar. 15,        2013;    -   (2) U.S. Provisional Application No. 61/870,065, filed Aug. 26,        2013 and U.S. patent application Ser. No. 13/893,890, filed May        14, 2013, which is a continuation-in-part of U.S. patent        application Ser. No. 13/861,137, filed Apr. 11, 2013, which is a        continuation-in-part of U.S. patent application Ser. No.        13/839,669, filed Mar. 15, 2013, which is a continuation-in-part        of U.S. patent application Ser. No. 13/589,829, filed Aug. 20,        2012;    -   (3) U.S. patent application Ser. No. 13/359,914, filed Jan. 27,        2012; and    -   (4) U.S. patent application Ser. No. 13/758,979, filed Feb. 4,        2013, which is a continuation-in-part of U.S. patent application        Ser No. 13/561,934, filed Jul. 30, 2012, which is a        continuation-in-part of U.S. patent application Ser. No.        13/075,574, filed Mar. 30, 2011, which is a continuation-in-part        of U.S. patent application Ser. No. 12/882,627, filed Sep. 15,        2010,    -   all of which are incorporated herein in their entireties.

FIELD OF THE INVENTION

The present invention relates generally to agricultural equipment and,more particularly, to row crop implements having automatic controlsystems.

SUMMARY

In accordance with one embodiment, an agricultural implement is providedfor use with a towing frame hitched to a tractor having a hydraulicsystem for supplying pressurized hydraulic fluid to the implement. Theimplement includes at least one row unit having (1) an attachment frameadapted to be rigidly connected to the towing frame, (2) a plurality ofsupport members, each of which is pivotably coupled to the attachmentframe or another of the support members to permit vertical pivotingvertical movement of the support members, (3) a plurality ofsoil-engaging tools, each of which is coupled to at least one of thesupport members, (4) a plurality of hydraulic cylinders, each of whichis coupled to one of the support members for urging the respectivesupport member downwardly toward the soil, each of the hydrauliccylinders including a movable ram extending into the cylinder, (5) aplurality of hydraulic lines, each of which is coupled to one of thehydraulic cylinders for supplying pressurized hydraulic fluid to therespective cylinders, (6) a plurality of controllable pressure controlvalves, each of which is coupled to one of the hydraulic lines forcontrolling the pressure of hydraulic fluid supplied by the respectivehydraulic lines to the respective cylinders, (7) a plurality of sensors,each of which produces an electrical signal corresponding to apredetermined condition, and (8) at least one controller coupled to thesensor and the controllable pressure control valves, the controllerbeing adapted to receive the electrical signal from the sensors andproduce a control signal for controlling the pressure control valves.

In one implementation, the plurality of sensors include at least onesensor selected from the group consisting of a pressure sensor detectingthe force applied by one of the hydraulic cylinders to the supportmember to which that cylinder is coupled.

In accordance with another embodiment, an agricultural row unitattachable to a towing frame for movement over a field having varyinghardness conditions, comprises a soil-penetrating tool, a gauge wheelmounted for rolling engagement with the soil surface, and a sensorcoupled to the tool and the gauge wheel for detecting changes in thedifference between the vertical positions of the tool and the gaugewheel, and producing an output corresponding to the changes. Acontrollable actuator is coupled to the tool for applying a downwardpressure on the tool, and a control system is coupled to the actuatorand receiving the output of the sensor for controlling the actuator andthus the downward pressure on the tool.

In one implementation, the agricultural row unit is a planting row unitthat includes an opening device for opening a furrow into which seedscan be planted, and the soil-penetrating tool is at least one closingwheel for closing the furrow after seeds have been deposited into thefurrow.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may best be understood by reference to the followingdescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a perspective view of a planting row unit attached to a towingframe.

FIG. 2 is a partially sectioned side elevation of the planting row unitof FIG. 1 with the linkage that connects the row unit to the towingframe in a level position.

FIG. 3 is the same side elevation shown in FIG. 1 but with the linkagetilted upwardly to move the row unit to a raised position.

FIG. 4 is the same side elevation shown in FIG. 1 but with the linkagetilted downwardly to move the row unit to a lowered position.

FIG. 5 is a top plan view of the hydraulic cylinder and accumulator unitincluded in the row unit of FIGS. 1-4.

FIG. 6 is a vertical section taken along line 6-6 in FIG. 5.

FIG. 7 is a side elevation of the unit shown in FIGS. 5 and 6 connectedto a pair of supporting elements, with the support structures and theconnecting portions of the hydraulic cylinder shown in section.

FIGS. 8A and 8B are enlarged cross sectional views of the supportingstructures shown in section in FIG. 7.

FIG. 9 is an enlarged perspective of the right-hand end portion of FIG.1 with a portion of the four-bar linkage broken away to reveal themounting of the hydraulic cylinder/accumulator unit.

FIG. 10 is a schematic diagram of a first hydraulic control system foruse with the row unit of FIGS. 1-9.

FIG. 11 is a schematic diagram of a second hydraulic control system foruse with the row unit of FIGS. 1-9.

FIG. 12 is a diagram illustrating one application of the hydrauliccontrol system of FIG. 11.

FIG. 13 is a side elevation of a modified embodiment having thehydraulic control unit coupled to the closing wheels of the row unit;

FIG. 14 is a side elevation of a further modified embodiment having thehydraulic control unit coupled to the closing wheels of the row unit;

FIG. 15 is yet another modified embodiment having the hydraulic controlunit coupled to the closing wheels of the row unit;

FIG. 16 is a side elevation of another modified embodiment of ahydraulic control unit;

FIG. 17 is an enlarged section taken along the line 17-17 in FIG. 16;and

FIG. 18 is a schematic diagram of the hydraulic circuit in the unit ofFIGS. 16 and 17.

FIG. 19 is a perspective view of a standard configuration of a hydraulicsystem.

FIG. 20A is an exploded view of a standard configuration of a hydraulicassembly.

FIG. 20B is an assembled perspective view of FIG. 20A.

FIG. 21 is a perspective view of a hose connection manifold.

FIG. 22A is a top cross-sectional view of FIG. 20B.

FIG. 22B is a side cross-sectional view of FIG. 20B.

FIG. 23 is a rear perspective view of an alternative configuration ofthe hydraulic system of FIG. 19.

FIG. 24A is an exploded view of an alternative configuration of ahydraulic assembly.

FIG. 24B is an assembled perspective view of FIG. 24A.

FIG. 25A is a perspective view of a control manifold.

FIG. 25B is a left cross-sectional view of the control manifold of FIG.25A.

FIG. 25C is a right cross-sectional view of the control manifold of FIG.25A.

FIG. 26 is a top plan view of a hydraulic cylinder for a row unit.

FIG. 27A is a vertical section taken along line 27A-27A in FIG. 26.

FIG. 27B is an enlarged view of a ram leading area that is shown in FIG.27A.

FIG. 28A is a side elevation of a hydraulic control system withdouble-acting ram for use with a row unit.

FIG. 28B is an enlarged view illustrating a hydraulic control unit ofthe hydraulic control system of FIG. 28A.

FIG. 29 is a perspective view of an agricultural opener device withintegrated controller.

FIG. 30 is a schematic diagram of a hydraulic control system havingintegrated controllers in one or more row units.

FIG. 31 is a schematic diagram of a hydraulic control system for usewith a row unit.

FIG. 32 is a partial perspective of a linkage assembly with twoactuators for controlling a row unit.

FIG. 33 is a side illustration of the linkage assembly of FIG. 32.

FIG. 34 illustrates an actuator having two energy storage devices.

FIG. 35 illustrates a tractor towing a plurality of row units havingstatus indicators.

FIG. 36 is a perspective view of a soil-hardness sensing device attachedto a planting row unit.

FIG. 37 is a schematic side elevation illustrating the soil-hardnessdevice attached to the planting row unit.

FIG. 38 is a schematic diagram illustrating the determination ofhydraulic pressures for a planting row unit.

FIG. 39A is a side elevation of an agricultural system moving over softsoil conditions.

FIG. 39B is a side elevation of the agricultural system of FIG. 39A inwhich a soil-hardness sensing device is moving over hard soilconditions.

FIG. 39C is a side elevation of the agricultural system of FIG. 39B inwhich a planting row unit is moving over the hard soil conditions.

FIG. 40A is a schematic side elevation illustrating sensing of soilconditions and determining of hydraulic pressures for a planting rowunit.

FIG. 40B is a flowchart of an algorithm for adjusting a pressure appliedto a soil-hardness sensing device.

FIG. 40C is a flowchart of an algorithm for adjusting a user-definedvariable associated with a pressure applied to a planting row unit.

FIG. 40D is a flowchart of an algorithm for adjusting a user-definedvariable associated with a pressure applied to a row-clearing unit.

FIG. 41A is a top elevation illustrating an agricultural system in whicha plurality of planting row units are adjusted by two soil-hardnesssensing devices.

FIG. 41B is a side elevation illustrating the agricultural system ofFIG. 41B.

FIG. 42 is a side elevation illustrating an alternative embodiment ofthe soil-hardness sensing device with modular actuators.

FIG. 43 is a perspective view illustrating an alternative modular unit.

FIG. 44A is side elevation illustrating an alternative embodiment of thesoil-hardness sensing device with a modified blade arm.

FIG. 44B is an enlarged exploded illustration of a distal end of theblade arm.

FIG. 44C is a side elevation of a row unit having a ground hardnesssensor integrated with a furrow-closing device that includes a pair oftoothed wheels and a ground gauge wheel.

FIG. 44D is an enlarged sectional view of a proximity sensing deviceincluded in the ground hardness sensor in the row unit shown in FIG.44C.

FIG. 44E is the same side elevation shown in FIG. 44C, with the closingwheels at a higher elevation than shown in FIG. 44C.

FIG. 44F is an enlarged sectional view of the proximity sensor shown inFIG. 44D, with the closing wheels in the position shown in FIG. 44E.

FIG. 44G is an enlarged exploded perspective view of the closing wheelsupport arm shown in FIGS. 44C-44F, and the sensing device coupled tothe upper end of that support arm.

FIG. 45 is a schematic diagram of a hydraulic control system forcontrolling the hydraulic pressure in a hydraulic cylinder.

FIG. 46A is a schematic diagram of a modified hydraulic control systemfor controlling the hydraulic pressure in a hydraulic cylinder.

FIG. 46B is a waveform diagram illustrating different modes of operationprovided by the hydraulic control systems of FIGS. 45 and 46A.

FIG. 46C is a diagrammatic illustration of an electrical control systemfor use with the hydraulic control systems of FIGS. 45 and 46A.

FIG. 47 is a side elevation of a planting row unit and a row-clearingunit, both attached to a towing frame, with the row-clearing unit in alowered position.

FIG. 48 is the same side elevation shown in FIG. 47 with therow-clearing unit in a raised position.

FIG. 49 is an enlarged perspective of the row-clearing unit shown inFIGS. 47 and 48.

FIGS. 50, 51 and 52 are side elevations of the main components of therow-clearing unit shown in FIGS. 47-49 in three different verticalpositions.

FIGS. 53, 54 and 55 are side elevations of the hydraulic cylinder of therow-clearing unit shown in FIGS. 47-52 with the cylinder rod in threedifferent positions corresponding to the positions shown in FIGS. 51, 52and 50, respectively.

FIG. 56 is a schematic diagram of a first hydraulic control system foruse in controlling the row-clearing unit shown in FIGS. 47-52.

FIG. 57 is a schematic diagram of a second hydraulic control system foruse in controlling the row-clearing unit shown in 47-52.

FIG. 58 is a functional block diagram of a hydraulic control system foruse with multiple row units.

FIG. 59 is a perspective view similar to that of FIG. 49 but modified toinclude a pressure sensor, in the form of a load cell.

FIG. 60 is an enlarged section view taken longitudinally through themiddle of the load cell shown in FIG. 59.

FIG. 61 is a side elevation of a modified embodiment having multiplecontrol systems.

FIG. 62 is a block diagram of the multiple control systems for multiplerow units of the type illustrated in FIG. 61, and a display coupled tothe control systems in the multiple row units.

FIG. 63 is a block diagram of a slightly simplified version of thesystem illustrated in FIG. 62.

FIG. 64 is a block diagram of a further simplified version of the systemillustrated in FIG. 62.

FIG. 65 is a block diagram of multiple control valves for multiple rowunits arranged in multiple groups or sections.

FIG. 66A is an exemplary display configured to depict real-time graphicswhen an implement is moving across a field.

FIG. 66B is an exemplary display depicting real-time graphics of one ormore performance metrics relating to a tool as it is moving across afield.

FIG. 66C is an exemplary display depicting a modified screen formonitoring one or more parameters associated with one or more toolsacross all the row units of a planter.

FIG. 66D shows an exemplary number keypad that can be used by theoperator to quickly select a row unit for immediate monitoring as therow units are being moved across a field.

FIG. 66E is an exemplary display depicting an exemplary row diagnosticsscreen with tool parameter monitor windows.

FIG. 67 is a series of plots representing the variations in electricalparameters representing the performance of an implement as it traversesan agricultural field.

FIG. 68 is an exemplary touch-screen display depicting a control panelfor use by an operator to select the type of tool to be monitored on thedisplay.

FIG. 69 is exemplary display depicting an interactive map screen.

FIG. 70 is a flowchart of an algorithm that can be used in connectionwith FIG. 40B.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Although the invention will be described in connection with certainpreferred embodiments, it will be understood that the invention is notlimited to those particular embodiments. On the contrary, the inventionis intended to cover all alternatives, modifications, and equivalentarrangements as may be included within the spirit and scope of theinvention as defined by the appended claims.

Turning now to the drawings, a planting row unit 10 includes afurrow-opening device for the purpose of planting seed or injectingfertilizer into the soil. In the illustrated embodiment, thefurrow-opening device is a V-opener 11 formed by a pair of conventionaltilted discs depending from the leading end of a row unit frame 12. Itwill be understood that other furrow-opening devices may be used. Aconventional elongated hollow towing frame 13 (typically hitched to atractor by a draw bar) is rigidly attached to the front frame 14 of aconventional four-bar linkage assembly 15 that is part of the row unit10. The four-bar (sometimes referred to as “parallel-bar”) linkageassembly 15 is a conventional and well known linkage used inagricultural implements to permit the raising and lowering of toolsattached thereto.

As the planting row unit 10 is advanced by the tractor, the V-opener 11penetrates the soil to form a furrow or seed slot. Other portions of therow unit 10 then deposit seed in the seed slot and fertilizer adjacentto the seed slot, and close the seed slot by distributing loosened soilinto the seed slot with a pair of closing wheels 16. A gauge wheel 17determines the planting depth for the seed and the height ofintroduction of fertilizer, etc. Bins 18 a and 18 b on the row unitcarry the chemicals and seed which are directed into the soil. Theplanting row unit 10 is urged downwardly against the soil by its ownweight, and, in addition, a hydraulic cylinder 19 is coupled between thefront frame 14 and the linkage assembly 15 to urge the row unit 11downwardly with a controllable force that can be adjusted for differentsoil conditions. The hydraulic cylinder 19 may also be used to lift therow unit off the ground for transport by a heavier, stronger,fixed-height frame that is also used to transport large quantities offertilizer for application via multiple row units.

The hydraulic cylinder 19 is shown in more detail in FIGS. 5 and 6.Pressurized hydraulic fluid from the tractor is supplied by a hose 20 toa port 21 that leads into a matching port 22 of a housing 23 that formsa cavity 24 of a hydraulic cylinder containing a ram 25. The housing 23also forms a side port 26 a that leads into cavity 26 b that contains agas-charged hydraulic accumulator 27. The lower end of the cavity 24 isformed by the top end surface of the ram 25, so that the hydraulicpressure exerted by the hydraulic fluid on the end surface of the ram 25urges the ram downwardly (as viewed in FIG. 6), with a force determinedby the pressure of the hydraulic fluid and the area of the exposed endsurface of the ram 25. The hydraulic fluid thus urges the ram 25 in anadvancing direction (see FIG. 4).

As can be seen most clearly in FIG. 9, the hydraulic cylinder 19 and theaccumulator 27 are mounted as a single unit on the front frame 14, withthe lower end of the ram 25 connected to a cross bar 30 that is joinedat one end to a vertical link 31. The upper and lower ends of the link31 are pivotably attached to upper and lower links 15 a and 15 b,respectively, on one side of the four-bar linkage 15. The other end ofthe cross bar 30 is angled upwardly and pivotably attached to the upperlink 15 c on the opposite side of the four-bar linkage 15. With thismounting arrangement, retracting movement of the ram 25 into the cavity24 tilts the linkage assembly 15 downwardly, as depicted in FIG. 3,thereby lowering the row unit. Conversely, advancing movement of the ram25 tilts the linkage assembly 15 upwardly, as depicted in FIG. 4,thereby raising the row unit.

The accumulator 27 includes a diaphragm 28 that divides the interior ofthe accumulator into a hydraulic-fluid chamber 29 a and a gas-filledchamber 29 b, e.g., filled with pressurized nitrogen. FIG. 2 shows theram 25 in a position where the diaphragm 28 is not deflected in eitherdirection, indicating that the pressures exerted on opposite sides ofthe diaphragm are substantially equal. In FIG. 3, the ram 25 has beenretracted by upward movement of the row unit, and the diaphragm 28 isdeflected downwardly by the hydraulic fluid forced into the accumulator27 by the retracting movement of the ram 25. In FIG. 4, the ram 25 hasbeen moved to its most advanced position, and the diaphragm 28 isdeflected upwardly by the air pressure as hydraulic fluid flows from theaccumulator into the cavity 24. The use of this compact hydraulicdown-force unit with an integral accumulator on each row unit providesthe advantages of quick response and remote adjustability of a hydraulicdown-force control system. If an obstruction requires quick movement,oil can flow quickly and freely between the force cylinder and theadjacent accumulator, without exerting force on other actuators in thesystem.

As can be seen in FIG. 4, advancing movement of the ram 25 is limited byengagement of stops 40, 42 on the lower links of the four-bar linkage15, with the row unit frame 12. This prevents any further advancement ofthe ram 25. Advancing movement of the ram 25 expands the size of thecavity 24 (see FIG. 4), which causes the diaphragm 28 in the accumulator27 to deflect to the position illustrated in FIG. 4 and reduce theamount of hydraulic fluid in the accumulator 27. When the ram 25 is inthis advanced position, the row unit is in its lowermost position.

In FIG. 3, the ram 25 has been withdrawn to its most retracted position,which can occur when the row unit encounters a rock or otherobstruction, for example. When the ram 25 is in this retracted position,the row unit is in its uppermost position. As can be seen in FIG. 3,retracting movement of the ram 25 is limited by engagement of stops 40,42 on the lower links of the four-bar linkage 15, with the row unitframe 12.

Retracting movement of the ram 25 reduces the volume of the cavity 24(see FIG. 3), which causes a portion of the fixed volume of hydraulicfluid in the cylinder 19 to flow into the chamber 29 a of theaccumulator 27, causing the diaphragm 28 to deflect to the positionillustrated in FIG. 3. This deflection of the diaphragm 28 into thechamber 29 b compresses the gas in that chamber. To enter the chamber 29a, the hydraulic fluid must flow through a port 32 in the top of theaccumulator 27, which limits the rate at which the hydraulic fluid flowsinto the accumulator. This controlled rate of flow of the hydraulicfluid has a damping effect on the rate at which the ram 25 retracts oradvances, thereby avoiding sudden large movements of the moving parts ofthe row unit, including the V-opener 11. This effect also minimizesvibration to improve accuracy of seed metering.

When the external obstruction causing the row unit 10 to rise iscleared, the combined effects of the pressurized gas in the accumulator27 on the diaphragm 28 and the pressure of the hydraulic fluid returnthe ram 25 to a lower position. This downward force on the V-opener 11holds it in the soil and prevents uncontrolled bouncing of the V-opener11 over irregular terrain. The downward force applied to the V-opener 11can be adjusted by changing the pressure of the hydraulic fluid suppliedto the cylinder 19.

As can be seen in FIGS. 5 and 6, the single unitary housing 23 formsboth the cavity 26 b that contains the accumulator 27 and the cavity 24of the hydraulic cylinder 19 and the fluid passageway 24 that connectsthe cavity 24 of the hydraulic cylinder 19 to the cavity 27 of theaccumulator. By integrating the hydraulic cylinder 19 and theaccumulator 27 in a single housing, there is no relative motion possiblebetween the cylinder 19 and the accumulator 27, with minimal possibilityfor fluid passageways to act like orifices. The cylinder 19 and theaccumulator 27 remain in fixed positions relative to each otherregardless of the movements of the planter row unit via the linkageassembly 15. In this way the upward motion of the ram 25 that occurswhen the planter row unit rolls over an obstruction is directlyconverted into compression of the gas in the accumulator 27 withoutrestriction. It also allows the accumulator 27, which is by definitionan energy storage device, to be mounted in a fully enclosed and safehousing. The accumulator 27 can be securely mounted to avoid puncture orrapid discharge (if it comes loose), or damage from hitting another partof the implement or a foreign object. The integrated cylinder andaccumulator is also a convenient single package for installation andreplacement and minimizes the number of hydraulic hoses and adapters(potential leakage points).

FIGS. 7, 8A and 8B illustrate in more detail how the illustrativehydraulic cylinder/accumulator unit is attached to the front frame 14and the linkage assembly 15. The top of the unitary housing 23 forms astem 41 that projects upwardly through a hole 51 in a bracket 50attached to the front frame 14. The outer surface of the stem 41 isthreaded to receive a nut 52 that connects the housing 23 to the bracket50. The hole 51 is oversized and a rubber washer is installed on thestem 41 between the nut 52 and the bracket 50 to allow a limited amountof tilting movement of the housing relative to the bracket 50. At thebase of the stem 41, beneath the bracket 50, the housing 23 forms ashoulder 43 that engages a conical bearing ring 53 that also engages amating lower surface of a washer 54. Thus, the housing 23 can be tiltedrelative to the axis of the hole 51, with the shoulder 43 sliding overthe lower surface of the bearing ring 53.

A similar arrangement is provided at the lower end of the ram 25, wherea stem 60 extends downwardly through a hole 61 in the cross bar 30 thatis pivotably attached to the linkage assembly 15. A nut 62 is threadedonto the stem 60 to connect the ram to the cross bar 30. The hole 61 isoversized and a rubber washer is installed on the stem 60 between thenut 62 and the cross bar 30 to allow a limited amount of tiltingmovement of the ram 25 relative to the cross bar 30. Above the cross bar30, a flange 63 on the ram 25 forms a curved conical surface 64 thatengages a mating surface of a curved conical bearing ring 65 that alsoengages a mating upper surface of a washer 66. Thus, the ram 25 can betilted relative to the axis of the hole 61, with the flange 63 slidingover the upper surface of the bearing ring 65.

The use of a hydraulic system permits on-the-go adjustments to be madevery rapidly because the hydraulic fluid is incompressible and thereforeacts more directly than an air system. In addition, hydraulic fluidstypically operate at higher pressures, which allow greater changes inapplied forces. The accumulator 27 allows the fluid system to flex andfloat with the changing terrain and soil conditions. The accumulator 27is preferably centrally mounted so that when any single row unit movesover an obstruction, the down-pressure cylinder 19 moves to displace thehydraulic fluid along a common set of lines connecting all row units.The gas in the accumulator is compressed at the same time, allowing forisolation among the row units so that upward movement of one row unitdoes not cause downward movement of other row units. Although theillustrative hydraulic ram is single-acting, it is also possible to usea double-acting ram, or a single-acting ram in combination with a returnspring.

Another advantage of the compact hydraulic cylinder/accumulator unit isthat it can be conveniently mounted to the same brackets that areprovided in many row units for mounting an air bag, to control the downpressure on the row unit. For example, in FIG. 9, the brackets 50 and 51on which the hydraulic cylinder/accumulator is mounted are the bracketsthat are often connected to an air bag, and thus the same row unit canbe used interchangeably with either an air bag or the hydrauliccylinder/accumulator to control the down pressure on the row unit.

FIG. 10 is a schematic of a hydraulic control system for supplyingpressurized hydraulic fluid to the cylinders 19 of multiple row units. Asource 100 of pressurized hydraulic fluid, typically located on atractor, supplies hydraulic fluid under pressure to a valve 101 viasupply line 102 and receives returned fluid through a return line 103.The valve 101 can be set by an electrical control signal S1 on line 104to deliver hydraulic fluid to an output line 105 at a desired constantpressure. The output line 105 is connected to a manifold 106 that inturn delivers the pressurized hydraulic fluid to individual feed lines107 connected to the ports 21 of the respective hydraulic cylinders 19of the individual row units. With this control system, the valve 101 isturned off, preferably by a manually controlled on/off valve V, afterall the cylinders 19 have been filled with pressurized hydraulic fluid,to maintain a fixed volume of fluid in each cylinder.

FIG. 11 is a schematic of a modified hydraulic control system thatpermits individual control of the supply of hydraulic fluid to thecylinder 19 of each separate row unit via feed lines 107 connected tothe ports 21 of the respective cylinders 19, or to control valves forthose cylinders. Portions of this system that are common to those of thesystem of FIG. 10 are identified by the same reference numbers. Thedifference in this system is that each separate feed line 107 leading toone of the row units is provided with a separate control valve 110 thatreceives its own separate control signal on a line 111 from a controller112. This arrangement permits the supply of pressurized hydraulic fluidto each row unit to be turned off and on at different times by theseparate valve 110 for each unit, with the times being controlled by theseparate control signals supplied to the valves 110 by the controller112. The individual valves 110 receive pressurized hydraulic fluid viathe manifold 106, and return hydraulic fluid to a sump on the tractorvia separate return line 113 connected to a return manifold 114connected back to the hydraulic system 100 of the tractor.

FIG. 12 illustrates on application for the controllable hydrauliccontrol system of FIG. 11. Modern agricultural equipment often includesGPS systems that enable the user to know precisely where a tractor islocated in real time. Thus, when a gang of planting row units 120 towedby a tractor 121 begins to cross a headland 122 in which the rows 123are not orthogonal to the main rows 124 of a field, each planting rowunit 120 can be turned off just as it enters the headland 122, to avoiddouble-planting while the tractor 121 makes a turn through the headland.With the control system of FIG. 11, the hydraulic cylinder 19 of eachrow unit can also be separately controlled to turn off the supply ofpressurized hydraulic fluid at a different time for each row unit, sothat each row unit is raised just as it enters the headland, to avoiddisrupting the rows already planted in the headland.

One benefit of the system of FIG. 11 is that as agricultural planters,seeders, fertilizer applicators, tillage equipment and the like becomewider with more row units on each frame, often 36 30-inch rows or 5420-inch rows on a single 90-foot wide toolbar, each row unit can floatvertically independently of every other row unit. Yet the following rowunits still have the down force remotely adjustable from the cab of thetractor or other selected location. This permits very efficientoperation of a wide planter or other agricultural machine in varyingterrain without having to stop to make manual adjustment to a largenumber of row units, resulting in a reduction in the number of acresplanted in a given time period. One of the most important factors inobtaining a maximum crop yield is timely planting. By permitting remotedown force adjustment of each row unit (or group of units), includingthe ability to quickly release all down force on the row unit whenapproaching a wet spot in the field, one can significantly increase theplanter productivity or acres planted per day, thereby improving yieldsand reducing costs of production.

On wide planters or other equipment, at times 90 feet wide or more andplanting at 6 mph or more forward speed, one row unit must often rise orfall quickly to clear a rock or plant into an abrupt soil depression.Any resistance to quick movement results in either gouging of the soilor an uncleared portion of the field and reduced yield. With the rowunit having its own hydraulic accumulator, the hydraulic cylinder canmove quickly and with a nearly constant down force. Oil displaced by orrequired by quick movement of the ram is quickly moved into or out ofthe closely mounted accumulator which is an integral part of each rowunit. The accumulator diaphragm or piston supplies or accepts fluid asrequired at a relatively constant pressure and down force as selectedmanually or automatically by the hydraulic control system. By followingthe soil profile closely and leaving a more uniform surface, thetoolbar-frame-mounted row unit permits the planter row unit followingindependently behind to use less down force for its function, resultingin more uniform seed depth control and more uniform seedling emergence.More uniform seedling stands usually result in higher yields than lessuniform seedling stands produced by planters with less accurate rowcleaner ground following.

FIGS. 13-15 illustrate modified embodiments in which the hydrauliccylinder 200 urges the closing wheels 16 downwardly with a controllableforce that can be adjusted for different conditions. Referring first toFIG. 13, pressurized hydraulic fluid from the tractor is supplied by ahose 201 to a port 202 of a housing 203 that forms a cavity of ahydraulic cylinder 204 containing a ram 205. The housing 203 also formsa side port 206 that leads into a cavity 207 that contains a gas-chargedhydraulic accumulator 208. The lower end of the cavity 204 is formed bythe top end surface of the ram 205, so that the hydraulic pressureexerted by the hydraulic fluid on the end surface of the ram 205 urgesthe ram downwardly (as viewed in FIG. 13), with a force determined bythe pressure of the hydraulic fluid and the area of the exposed endsurface of the ram 205. The hydraulic fluid thus urges the ram 205 in adownward direction.

The hydraulic cylinder 204 and the accumulator 208 are pivotably mountedas a single unit on the row unit frame 210, with the lower end of theram 205 pivotably connected to a linkage 211 that carries the closingwheels 16. With this mounting arrangement, advancing movement of the ram205 in the cylinder 204 tilts the linkage 211 downwardly, thereby urgingthe closing wheels 16 downwardly. Conversely, retracting movement of theram 205 tilts the linkage 211 upwardly, thereby raising the closingwheels 16.

FIG. 14 illustrates an arrangement similar to FIG. 13 except that thehydraulic cylinder 204 is charged with a pressurized gas in chamber 212on the side of the ram 205 that is not exposed to the pressurized fluidfrom the hose 201. Thus, as the ram 205 is retracted by increasing thehydraulic pressure on one side of the ram, the gas on the other side ofthe ram is compressed and thus increases the resistance to retractingmovement of the ram. The hydraulic cylinder 204 is positioned such thatadvancing movement of the ram 205 in the cylinder 204 tilts the linkage211 upwardly, thereby raising the closing wheels 16. Conversely,retracting movement of the ram 205 tilts the linkage 211 downwardly,thereby urging the closing wheels 16 downwardly with an increased force.To increase the downward pressure on the closing wheels 16, thehydraulic pressure must overcome the gas pressure that increases as theram 205 is retracted, but upward movement of the closing wheels (e.g.,when an obstruction is encountered) requires only that the ram beadvanced with sufficient pressure to overcome that of the hydraulicfluid.

In FIG. 15, the arrangement is the same as in FIG. 14, but the hydrauliccontrol unit has an added biasing element 220 on the side of the ram 205that is not exposed to the pressurized hydraulic fluid. This biasingelement 220 may be in addition to, or in place of, pressurized gas inthe hydraulic cylinder 204. The biasing element 220 may be formed byvarious types of mechanical springs, such as a compressed coil spring,or may be pressurized air, nitrogen or other gas.

FIGS. 16-18 illustrate a modified hydraulic control unit that includes ahydraulic cylinder 300 containing a ram 301 that can be coupled at itslower end to a device on which the down pressure is to be controlled.Pressurized hydraulic fluid is supplied to the upper end of the cylinder301 through a port 304. The cylinder 300 includes a side port 302leading to an accumulator 303 of the type described above in connectionwith FIGS. 5 and 6. The entry port 305 to the accumulator 303 isequipped with a check valve 306 and restriction 307 as illustrated inFIG. 18. When the ram 301 is in a lowered position that opens the port302, and is moved upwardly by an upward force applied by engagement ofthe controlled device with a rock or other obstruction, hydraulic fluidflows from the cylinder 300 into the accumulator 303 via the restriction307. The restriction acts as a damper to reduce the shock on theequipment and avoid excessive upward movement of the ram 301. When theupward force on the ram has been removed, hydraulic fluid flows from theaccumulator back into the cylinder 300 via the check valve 306, whichallows unrestricted flow in this direction so that the controlled devicequickly re-engages the ground with the down pressure exerted by thehydraulic fluid on the upper end of the ram 301. The check valve unitcan be easily installed in the accumulator entry port 305. Additionally,the check valve unit can have an orifice system that is bidirectionalfor damping motion, both in and out.

The term row unit refers to a unit that is attached to a towing frame ina way that permits the unit to move vertically relative to the towingframe and other units attached to that same towing frame. Most row unitsare equipped to form, plant and close a single seed furrow, but rowunits are also made to form, plant and close two or more adjacent seedfurrows.

Referring to FIG. 19, a hydraulic system 400 includes a hydraulicassembly 401, a front frame 404, and a four-bar linkage assembly 406.The four-bar linkage assembly 406 is generally similar to the four-barlinkage assembly 15 described above in reference to FIGS. 1-9. Thefour-bar linkage assembly 406 includes a pair of parallel lower links408 a, 408 b, a pair of parallel upper links 410 a, 410 b, and a crossbar 412. The hydraulic assembly 401 is rigidly attached to the four-barlinkage assembly 406 on a row-unit side, and the front frame 404 ispivotably attached to the four-bar linkage assembly 406 on a towingside.

The hydraulic assembly 401 includes a hydraulic cylinder 402, anaccumulator protective cover 420, and a hose connection manifold 424.The hydraulic cylinder 402 is generally similar to the hydrauliccylinders 19, 204 described above in reference to FIGS. 1-9 and 13-18,and includes an upper end 413 a and a lower end 413 b. The upper end ismounted to a bracket 414 of the linkage assembly 406, and the lower end413 b is mounted to the cross bar 412 of the linkage assembly 406. Agland and securing nut 418 (with internal seals) is interposed at thelower end 413 b between the hydraulic cylinder 402 and the cross bar412.

The accumulator protective cover 420 is mounted adjacent to and betweena left upper link 410 b and the hydraulic cylinder 402. The accumulatorprotective cover 420 shields from environmental contaminants andphysical damage an accumulator 422 (shown in FIG. 20A). In addition toprotecting the accumulator 422, the accumulator protective cover 420itself is provided with protection from physical damage, e.g., caused bydebris, rocks, etc., by being located between the pair of upper links410 a, 410 b. Although the upper links 410, 410 b do not completelyshield the accumulator protective cover 420, the upper links 410, 410 bprovide some protection from physical damage while, simultaneously,allowing ease of access for servicing and/or replacing the accumulator422.

The hose connection manifold 424, which is described in more detailbelow in reference to FIG. 21, is mounted adjacent to and between aright upper link 410 a and the hydraulic cylinder 402. The hoseconnection manifold 424 is configured such that it does not interferewith any of the other components of the hydraulic system 400, includingthe right upper link 410 a, the hydraulic cylinder 402, and theaccumulator protective cover 420. The hose connection manifold 424 iscoupled at a distal end to a pair of hydraulic fluid hoses, including aninlet hose 426 and an outlet hose 428. Assuming a configuration in whicha plurality of units are arranged in a parallel (or side-by-side)configuration, the inlet hose 426 receives and delivers hydraulic fluidfrom an adjacent row unit, and the outlet hose 428 connects to anotheradjacent row unit.

The attachment of the hoses 426, 428 to the hose connection manifold424, in a position that is spaced away from the relativelymore-cluttered area of the hydraulic cylinder 402 and bracket 414,facilitates easy field servicing of the hoses 426, 428. For example, auser can easily couple/uncouple the hoses 426, 428 to/from the hoseconnection manifold 424 by having a clear path directly to the hoseconnection manifold 424.

Referring to FIGS. 20A and 20B, the accumulator protective cover 420includes a right cover 420 a and a left cover 420 b that are fastened toeach other via a plurality of small nuts 434 and bolts 436. Enclosedwithin the accumulator protective cover 420 is the accumulator 422,which has an accumulator end 430 that is inserted into a accumulatorreceiver 432 of the hydraulic cylinder 402. The accumulator receiver 432extends from a main body 433 of the hydraulic cylinder 402 a sufficientdistance to permit the mounting of the accumulator protective cover 420without interfering with the hose connection manifold 424 (as furtherillustrated in FIG. 22A).

The main body 433 of the hydraulic cylinder 402 receives a spherical rod438 for axial mounting below the accumulator receiver 432. The gland 418is threaded into the hydraulic cylinder 402 after the spherical rod 438is installed on the hydraulic cylinder 402. The gland 418 containsinternal seals and wear rings to hold pressure and seal outcontaminants.

The hydraulic cylinder 402 further includes a mounting interface 440extending from the main body 433 in an opposite direction relative tothe accumulator receiver 432. The hose connection manifold 424 ismounted directly to the mounting interface 440 via a plurality of longbolts 442 that are received, respectively, in a plurality of threadedholes 444. An O-ring seal 441 is positioned between the control manifold424 and the hydraulic cylinder 402 to prevent leakage of hydraulicfluid. The hose connection manifold 424 has a mounting face 456 (shownin FIG. 21) that is aligned, when mounted, in contact with a receivingface 443 of the mounting interface 440. As illustrated in the exemplaryembodiment, the mounting face 456 of the hose connection manifold 424and the receiving face 443 of the mounting interface 440 are configuredsuch that they are complementary mating faces with the O-ring seal 441holding pressure between the components.

The mounting interface 440 further facilitates a modular exchangebetween hose connection manifolds of different types. In the currentillustration, the hose connection manifold 424 is an example of astandard configuration in which the manifold functions solely to attachhydraulic hoses and to circulate hydraulic fluid between the hydraulicsource and the hydraulic cylinder 402. In an alternative configuration,described in more detail below in reference to FIGS. 23-25C, the samemounting interface 440 (without reliance on additional components ortools) is used to attach a manifold of a different type. This modularexchange between different manifold types is beneficial for quick andeasy replacement of the manifolds based on current planting needs, whichcan quickly change in real time due to weather conditions, terrainconditions, etc.

A pair of hose ends 446, 448 are attached to the hose connectionmanifold 424 at a distal end 450 for coupling the inlet and outlet hoses426, 428. Specifically, an inlet hose-end 446 is coupled to the inlethose 426 and an outlet hose-end 446 is coupled to the outlet hose 428.The hose ends 446, 448 are attached to the distal end 450 in a generallyparallel configuration relative to a central axis of the hydrauliccylinder 402. As discussed above, the attachment configuration of thehose ends 446, 448 to the hose connection manifold 424 facilitates easyaccess and servicing of the inlet and outlet hoses 426, 428.

Referring to FIG. 21, the hose connection manifold 424 is a valve-lessmanifold that lacks a control valve or a control module (in contrast tothe integrated control manifold 524 discussed below in reference toFIGS. 23-25C). The hose connection manifold 424 has a mounting end 452that is separated from the distal end 450 by a manifold arm 454. Themanifold arm 454 includes a curved section that offsets the mountingface 456 of the mounting end 452 by a distance D from an exteriorsurface 466 of the distal end 450. The offset distance D is helpful inminimizing space requirements for mounting the hose connection manifold424 within the space defined by the upper links 410, 410 b of thelinkage assembly 406. The manifold arm 454 is positioned generallyparallel to the accumulator 422.

The mounting face 456 includes a plurality of mounting holes 458arranged in a concentric pattern around a central hydraulic hole 459,through which hydraulic fluid is delivered to the hydraulic cylinder402. The pattern of the mounting holes 458 matches a pattern of thethreaded holes 444 of the mounting interface 440. When the hoseconnection manifold 424 is mounted to the hydraulic cylinder 402, thelong bolts 442 are received through the mounting holes 458.

The hydraulic hole 459 is internally connected to an inlet port 460 andan outlet port 462 via an internal channel 464 (illustrated in FIG.22A). The inlet port 460 is adapted to receive the inlet hose-end 446,to which the inlet hose 426 is coupled, and the outlet port 462 isadapted to receive the outlet hose-end 446, to which the outlet hose 428is coupled. The inlet and outlet ports 460, 462 are aligned with acentral axis of the internal channel 464 and are oriented perpendicularto the orientation of the hydraulic hole 459. Additionally, the spacingbetween the inlet port 460 and the outlet port 462 facilitates parallelcoupling of the two hose ends 446, 448 adjacent to each other.

Referring to FIGS. 22A and 22B, the configuration of the hydraulicassembly 401 facilitates delivery of hydraulic fluid to the hydrauliccylinder 402 in a relatively space-constrained environment while stillproviding easy access to main components, including the accumulator 422and the hose connection manifold 424, for service and replacement. Forexample, referring specifically to FIG. 22A, hydraulic fluid circulatesunrestricted between the hose connection manifold 424, the hydrauliccylinder 402, and the accumulator 422 via the internal channel 464. Thegeometric configuration of the hose connection manifold 424 facilitatesmounting the accumulator protective cover 420 close to the distal end450 of the hose connection manifold 424 at a relatively small distanceZ, thus minimizing required mounting space, without causing interferencebetween the hose connection manifold 424 and the accumulator protectivecover 420.

In addition to the offset distance D, the distal end 450 is furtherdefined by a distance X that separates two extreme points of a centralaxis of the internal channel 464. Specifically, distance X is defined bya point of the central axis near the distal end 450 and a point of thecentral axis near the mounting end 452. Although the offsetting of thetwo ends 450, 452 does not impact the flow of hydraulic fluid, theoffsetting helps increase clearance space between the hose connectionmanifold 424 and the linkage assembly 406.

Referring more specifically to FIG. 22B, the inlet hose 426 and theoutlet hose 428 can be easily and quickly removed, in the field, basedat least on their parallel upward attachment to the hose connectionmanifold 424. Optionally, the inlet hose 426 and the outlet hose 428 canbe daisy chained when using a typical side-by-side arrangement of rowunits. For example, in one illustrative example, a first row unit isconnected directly to the hydraulic source via its inlet hose anddirectly to the inlet port of an adjacent second row unit via its outlethose. Thus, the second row unit receives hydraulic fluid, indirectly,from the hydraulic source via the first row unit. The second row unit,is further daisy chained to an adjacent third row unit such that theoutlet hose of the second row unit is directly connected to the inletport of the third row unit. This type of daisy-chain configuration cancontinue with dozens of row units. To change the configuration to astandard hose routing, one of the two ports 460, 462 is plugged and atee is placed in front of the row unit such that a single hose isconnected to the hydraulic cylinder 402.

Referring to FIG. 23, in an alternative configuration of the hydraulicsystem 400 the hose connection manifold 424 has been replaced with theintegrated control manifold 524 that includes both an electronic controlmodule 525 and a connection manifold 527 (both shown in FIGS. 24A and24B). The control manifold 524 is configured to fit within the upperlinks 410 a, 410 b next to the accumulator protective cover 420, similarto the hose connection manifold 424. Thus, similarly to the hoseconnection manifold 424, the control manifold 524 does not interferewith any components of the hydraulic system 400. Additionally, easyaccess is provided for a user to couple/uncouple the inlet and outlethoses 426, 428 to/from the control manifold 524. The control manifold524 is further connected to a control signal wire 529 for receivingcontrol signals from a central processing unit.

One benefit of the control manifold 524 is that each row unit of aplurality of adjacent row units (in a side-by-side arrangement of rowunits) has its own pressure control valve. Assuming that the controlmanifold 524 is mounted in each of the plurality of row units, the downpressure in each row unit can be individually controlled. To achieveindividual control, both the inlet hose 426 and the outlet hose 428 ofeach row unit are connected to the hydraulic source in parallel. Forexample, the inlet hose of a first row unit is connected to the tractorfor supplying constant pressure to the first row unit, and the outlethose of the first row unit is also connected to the tractor forreturning hydraulic fluid from the first row unit. Similarly, the inlethose of a second row unit is connected to the tractor for supplyingconstant pressure to the second row unit, and the outlet hose of thesecond row unit is also connected to the tractor for returning hydraulicfluid from the second row unit. According to this example, the pressurein the first and second row units can be independently controlled.

Referring to FIGS. 24A-24B, the control manifold 524 is mounted to thehydraulic cylinder 402 using the same long bolts 442, which are fastenedto the threaded holes 444. The control manifold 524 has a mating face556 (shown in FIGS. 25A-25C) that is generally similar (if notidentical) to the mating face 456 of the hose connection manifold 424.The mating face 556 is configured as a mating face for facilitatingattachment of the control module 524 to the mounting interface 440(similar to the attachment of the hose connection manifold 424 to themounting interface 440). An O-ring seal 541 is positioned between thecontrol manifold 524 and the hydraulic cylinder 402 to prevent leakageof hydraulic fluid.

The hose ends 446, 448 are received in respective inlet and outlet ports560, 562 for facilitating coupling of the hoses 426, 428 to the controlmodule 542. In contrast to the inlet and outlet ports 460, 462 of thehose connection manifold 424, the inlet and outlet ports 560, 562 of thecontrol manifold 524 are oriented perpendicular to (not parallel to) thecentral axis of the hydraulic cylinder 402. Nevertheless, a user canstill reach with relative ease the connection between hoses 426, 428 andthe ports 560, 562 for service-related needs.

The control module 525 includes a hydraulic valve cartridge 531 forreducing and/or relieving pressure in hydraulic cylinder 402. The valvecartridge 531 is enclosed within the control module 525 and has one endinserted in a cartridge port 533 of the connection manifold 527. Inresponse to receiving a control signal, via the control signal wire 529and the electrical connector 537, the valve cartridge 531 reducespressure in the hydraulic cylinder 402 and, optionally, acts as a reliefvalve relieving any shocks or surges that may occur between thehydraulic source and the hydraulic cylinder 402. The control module 525optionally includes a pressure transducer 535 and/or other embeddedelectronics.

For ease of access, an integrated electronic connector 537 of thecontrol module 525 is positioned above the valve cartridge 531 forreceiving electrical power via an electrical cable (not shown). Theelectronic connector 537 is angled towards the accumulator protectivecover 420 to provide sufficient space for connecting all the requiredcables and hoses to the control module 525, e.g., the inlet and outlethoses 426, 428, the control signal wire 529, and the electrical cable.

Referring to FIGS. 25A-25C, the connection manifold 527 is configured tofacilitate the integral combination with the control module 525. Forexample, the connection manifold 527 has a mounting face 556 that isaligned, when mounted with the receiving face 443 of the mountinginterface 440. The mounting face 556 of the connection manifold 527 isgenerally similar (if not identical) to the mounting face 456 of thehose connection manifold 424. For example, the mounting face 556includes a plurality of mounting holes 558 arranged in a concentricpattern around a central hydraulic hole 559, through which hydraulicfluid is delivered to the hydraulic cylinder 402. The pattern of themounting holes 558 matches a pattern of the threaded holes 444 of themounting interface 440. When the connection manifold 527 is mounted tothe hydraulic cylinder 402, the long bolts 442 are received through themounting holes 558.

The hydraulic hole 559 is internally connected to the inlet port 560,the outlet port 562, the cartridge port 533, and a transducer port 539.In contrast to the hose connection manifold 424, the connection manifold527 includes the additional cartridge port 533 for coupling to the valvecartridge 531 (which controls output of fluid pressure from thehydraulic cylinder 402) and the transducer port 539 for coupling to thepressure transducer 535. The ports are positioned along a control face541, which is generally perpendicular to the mounting face 556. Thus,although the connection manifold 527 and the hose connection manifold424 share some similarities (e.g., sharing the modular mountinginterface 440), they are different in type at least based on theconnection manifold 527 being configured geometrically to facilitate theintegration with the control module 525.

Referring generally to FIGS. 26-27B, a hydraulic cylinder 619 and energystorage device 627 are generally similar to the hydraulic cylinder 19and accumulator 27 described and illustrated above in reference to FIGS.5 and 6. Referring specifically to FIG. 27A, a single unitary housing623 forms a cavity 624 in which the hydraulic cylinder 619 and theenergy storage device 627 are enclosed, at least in part. The hydrauliccylinder 619 contains a ram 625 that advances towards a housing port 622or retracts towards a stem 660.

Referring specifically to FIG. 27B, the ram 625 has a leading edge 650near which a wear ring 652 is mounted. The wear ring 652 is mounted onthe ram 625 concentric with a central axis Z of the ram 625 and inphysical contact (or close to being in physical contact) with a cylinderwall 654. The wear ring 652 can be a seal or some other component thatcan provide a barrier zone between the ram 625 and the cylinder wall654. The wear ring 652 can have a cylindrical cross-sectional profile(as illustrated in FIG. 27B) or any other cross-sectional profile.

The wear ring 652 guides the ram 625 within the cylinder wall 654 of thehydraulic cylinder 619, absorbing transverse forces. The wear ring 652further prevents (or reduces) metal-to-metal contact between the ram 625and the cylinder wall 654 and, thus, optimizes the performance of thehydraulic cylinder 619. As such, one benefit of the wear ring 652 isthat it prevents or reduces wear of the ram 625 due to frictionalcontact with the cylinder wall 654. Another benefit of the wear ring 652is that it tends to act as a seal component (although not necessarilyspecifically intended to be a seal component). For example, especiallyduring high-speed movement of the ram 625, tight tolerances between theram 625 and the cylinder wall 654 help achieve a sealing function thatprevents, or greatly reduces, undesired fluid flow between the ram 625and the cylinder wall 654. According to one example, the tighttolerances can range between 0.01 inches and 0.03 inches.

The ram 625 further includes a plurality of intersecting internalpassageways, including an axial passageway 660 and a radial passageway662. The axial passageway 660 starts at the leading edge 650 andcontinues partially within the ram 624, along the central axis Z, untilit intersects with the radial passageway 662. The radial passageway 662extends perpendicular to the central axis Z between the central axis Zand a peripheral wall of the ram 625.

Similar to a shock absorber, the internal passageways 660, 662 provide adampening feature to the hydraulic cylinder 610. Specifically, theinternal passageways 660, 662 equalize pressure on either side of thewear ring 652 (which tends to act as a seal at high-speed ramvelocities). While the hydraulic cylinder 619 is intended to generatepressure, the internal passageways 660, 662 integrate into the hydrauliccylinder 619 damping to control unwanted movement and or pressure. Assuch, the internal passageway 660, 662 are helpful in preventing damageto the hydraulic cylinder 619 by controlling the damping of thehydraulic cylinder 619. Optionally, in addition to acting as orificesfor controlling damping, the internal passageways 660, 662 can be usedfor mounting check valves to the ram 625. The check valves can furthercontrol the damping in the hydraulic cylinder 619. Accordingly, theinternal passageways 660, 662 provide a hydraulic cylinder with anintegrated damping-control system.

Referring to FIGS. 28A and 28B, a planting row unit 710 is generallysimilar to the planting row unit 10 described above. The planting rowunit 710 includes a V-opener 711, a row unit frame 712, a pair ofclosing wheels 716, and a gauge wheel 717 that are assembled andfunction similarly to the similarly numbered components of the plantingrow unit 10. The planting row unit 710 also includes a hydrauliccylinder 700 that urges the closing wheels 716 downwardly with acontrollable force that can be adjusted for different conditions.

The hydraulic cylinder 700 includes a double-acting ram 705 (whichfurther exemplifies the double-acting ram embodiment identified above inreference to the ram 25) that can move in opposing directions based onfluid pressure received from either a first hose 701 a or a second hose701 b. As such, hydraulic fluid is received via the hoses 701 a, 701 bto act alternately on both sides of the double-acting ram 705 and,consequently, apply alternate pressure in both directions of arrowsA-A′. The hydraulic cylinder 700 can, optionally, further includes abiasing element 720 (e.g., mechanical spring, compressed coil spring,pressurized gas) to further add pressure in addition to the pressureprovided by the double-acting ram 705. The biasing element 720 can beadded on either side of the double-acting ram 705.

One benefit of the double-acting ram 705 is that it can provide bothdown pressure or up pressure, as needed, for the planting row unit 710.For example, if additional pressure is required to cause the V-opener711 to penetrate the soil to a required depth, down pressure would beapplied. If, for example, the planting row unit 710 is too heavy and theV-opener 711 penetrates the soil in excess of the required depth, thenup pressure would be applied (without requiring an additional hydrauliccylinder).

Referring to FIG. 29, a disk opener 800 is adapted for attachment to arow unit, such as planting row unit 10 described above in reference toFIG. 1. The disk opener 800 includes a support 802 to which a swing arm804 is mounted for attaching a disk 806 and a gauge wheel 808. The disk806 penetrates the soil to a planting depth for forming a furrow or seedslot, as the row unit is advanced by a tractor or other towing vehicle.The gauge wheel 808 determines the planting depth for seeds and/orheight of introduction of fertilizer.

The disk opener 800 further includes a down-pressure cylinder 810, withan integrated control valve 812, that is mounted to a bracket 814. Thedown-pressure cylinder 810 is generally similar to the hydrauliccylinder 402 (e.g., illustrated in FIG. 19) and the integrated controlvalve 812 is generally similar to the control module 525 (e.g.,illustrated in FIG. 24A). The control valve 812 includes a solenoid 816that is generally similar to the electronic connector 537 (e.g.,illustrated in FIG. 24A).

In addition, the disk opener 800 includes a programmable-logiccontroller (PLC) or other computer control unit 818 that is also mountedto the bracket 814. Optionally, the control unit 818 is directlyintegrated into the control valve 812, e.g., into the solenoid 816.According to this optional embodiment, the control unit 818 would begenerally similar to the embedded electronics integrated with anddescribed above in reference to the control module 525. The control unit818 is coupled to a power supply via a control wire 820 and to thecontrol valve 812 via a valve wire 822. The control wire 820 optionallyfunctions to connect the control unit 818 with a control interface suchas found in a tractor.

An advantage of mounting the control unit 818 to the row unit, via thedisk opener 800, is that it provides better, and specific, control overthe control valve 812. As such, for example, each row unit in anarrangement having a plurality of side-by-side row units (such asillustrated below in FIG. 30) can be individually controlled to apply adesired down pressure specific to the corresponding row unit. Thus, thecontrol unit 818 runs a control algorithm that takes inputs anddetermines an output signal for the control valve 812.

Referring to FIG. 30, a hydraulic control system supplies pressurizedhydraulic fluid to cylinders of multiple row units. A source 900 ofpressurized hydraulic fluid, typically located on a tractor, supplieshydraulic fluid under pressure to an optional main valve 901 via asupply line 902 and receives returned fluid through a return line 903.The main valve 901 can be set by an electrical control signal S1 on line904 to deliver hydraulic fluid to an output line 905 at a desiredconstant pressure. The output line 905 is connected to a manifold 906that, in turn, delivers the pressurized hydraulic fluid to individualfeed lines 907 (which are connected to ports of respective hydrauliccylinders of the individual row units). Optionally, the main valve 901is turned off after all cylinders have been filled with pressurizedhydraulic fluid to maintain a fixed volume of fluid in each cylinder.

Each of the individual feed lines 907 leads to one of the row units andis provided with a separate control valve 910 that receives its ownseparate control signal on a line 911 from a respective controller 912(which is integrated in the respective row unit as described above inreference to FIGS. 24A and 30). The separate control valve 910 isprovided in addition to or instead of the valve 901. This arrangementpermits the supply of pressurized hydraulic fluid to each row unit to beturned off and on at different times by the separate control valve 910for each row unit, with the times being controlled by the separatecontrol signals supplied to the valves 910 by the respective controllers912. The individual valves 910 receive pressurized hydraulic fluid viathe manifold 906, and return hydraulic fluid to the tractor via separatereturn lines 913 connected to a return manifold 914, which is connectedback to the hydraulic system 900 of the tractor. Optionally, one or moreof the individual integrated controllers 912 are connected to a maincontroller 915 that provides control input for at least one of theintegrated controllers 912.

Referring to FIG. 31, an alternative configuration is illustrated inreference to the hydraulic control system described above in FIG. 30.The alternative configuration includes a tractor 950 that generateshydraulic auxiliary power bifurcated into two power subsets: a tractorhydraulic system (THS) 952 and a tractor power take-off (PTO) 954. Thetractor hydraulic system 952 is coupled to a hydraulically-drivenelectrical generator 956 for generating electricity for row unitcomponents such as the control valves 910 and/or other control modules(e.g., controllers 912, 915). The tractor PTO 954 is mechanical powerthat runs a hydraulic pump 958 to provide mechanical power for row unitcomponents such as hydraulic cylinders connected to the individual feedlines 907.

Providing both the hydraulic system 952 and the tractor PTO 954 helpsprovide additional electrical power for electrical components thatpreviously were not included in an agricultural system. For example,adding controllers 912, 915 and control valves 910 to each row unitresults in an increased need of electrical power relative toagricultural systems that, for example, lacked individual row-unitcontrol. The electrical generator 956 compensates for and provides therequired increased electricity.

Referring to FIGS. 32 and 33, a hydraulic cylinder system includes twohydraulic cylinders 1019 a, 1019 b, instead of a single actuator asdescribed above in reference to the hydraulic cylinder 19 (which isillustrated, for example, in FIG. 9). Each of the hydraulic cylinders1019 a, 1019 b is generally similar to the hydraulic cylinder 19.However, instead of coupling the single hydraulic cylinder 19 between afront frame and a linkage assembly, this alternative embodimentillustrates coupling the two hydraulic cylinders 1019 a, 1019 b betweena front frame 1014 and a linkage assembly 1015.

The hydraulic cylinders 1019 a, 1019 b are both mounted at one end to across bar 1030, which has been modified in this illustrative embodimentand relative to the cross bar 30 of FIG. 9 to have generally a Z-shape.Specifically, a first hydraulic cylinder 1019 a is mounted such that itcan apply down pressure D to the row unit and a second hydrauliccylinder 1019 b is mounted such that it can apply up pressure U to therow unit.

One advantage of having two cylinders 1019 a, 1019 b is that the rowunit can be controlled both up and down with more precision. Forexample, the controlled row unit may have a heavy weight that results ina furrow depth exceeding the desired planting depth. To counter theweight, the second hydraulic cylinder 1019 b is used to raise the rowunit such that the shallower depth is achieved. As such, the secondhydraulic cylinder 1019 b acts to subtract (or counter) at least some ofthe row-unit weight. If the row unit has a light weight that results ina shallower depth than desired, the first hydraulic cylinder 1019 a isused to lower the row unit such that the deeper depth is achieved. Assuch, the first hydraulic cylinder 1019 a acts to artificially addweight to the row unit.

Referring to FIG. 34, a hydraulic cylinder 1119 includes two storageenergy devices, which are illustrated in the form of a first accumulator1127 a and a second accumulator 1127 b. Each of the two accumulators1127 a, 1127 b is generally similar to the accumulator 27 (illustrated,for example, in FIG. 6). The hydraulic cylinder 1119 includes a ram 1125that acts similar to the double-acting ram 705 illustrated in FIGS. 28Aand 28B. The ram 1125 can provide both down pressure and up pressure, asneeded, for a planting row unit (e.g., planting row unit 710). Theaccumulators 1127 a, 1127 b act as shock absorbers to help relievepressure based on the direction of the applied pressure by thedouble-acting ram 1125. For example, the first accumulator 1127 arelieves pressure when the double-acting ram 1125 applies pressure in afirst direction D1 (e.g., down pressure), and the second accumulator1127 b relieves pressure when the double-acting ram 1125 appliespressure in a second direction D2 (e.g., up pressure).

The use of this hydraulic cylinder 1119, as a compact hydraulicdown-force unit with integral accumulators 1127 a, 1127 b on each rowunit, provides the advantages of quick response and remote adjustabilityof a hydraulic down-force and up-force control system. If an obstructionrequires quick movement, oil can flow quickly and freely between theforce cylinder 1119 and the respective adjacent accumulator 1127 a, 1127b, without exerting force on other actuators in the system.

Referring to FIG. 35, a controllable hydraulic control system 1200includes a plurality of row units 1202 that are towed by a vehicle 1204through a field. Each of the row units 1202 includes a status indicator1206 for signaling performance-related issues. According to one example,the status indicators 1206 are light-emitting diodes (LED) that providean easily discernible way to visually inspect the performance of the rowunits 1202. For example, the LED status indicators 1206 can flash a redcolor R to indicate improper tilling or a malfunction. If everythingperforms as intended, the status indicators 1206 can flash a green colorG.

The status indicator 1206 can be a single (larger) LED or a plurality ofLEDs of various sizes. Alternatively, the status indicator 1206 caninclude in addition to or instead of the LED an audible indicator tosignal a malfunction or other condition of the system 1200.

Optionally, the status indicators 1206 can be integrated with controlelectronics of the row units 1202 (e.g., control module 525 illustratedin FIG. 23) and can provide a status-check of the electronics. Thus, thestatus indicators 1206 are attached to each individual row unit 1202 toprovide a person that is far away from the row units 1202 a quick visualcheck on the performance status of the system 1200, including theperformance status of an electronic controller.

In another example, the status indicators 1206 are particularly helpfulin a system 1200 that is a human-less farming system. The human-lessfarming system is a system in which robotic machines are moving about inthe field to perform tilling, planting, and/or other agriculturalfunctions. Such a system is monitored by a farm manager that isstanding, for example, a quarter-mile away from the system. The statusindicators 1206 provide the farm manager with quick and easy visualsignals that indicate the performance of the system.

Optionally, the system 1200 further emits a wireless signal 1208 forcommunicating status performance to an online monitoring system. Theperformance of the system 1200 can be, then, evaluated using anelectronic device such as a smartphone.

Referring to FIG. 36, an agricultural system 2100 includes asoil-hardness sensing device 2102 attached in front of an agriculturalrow unit 2104 (also referred to as a planting row unit) via a towingframe 2106. The towing frame 2106 is generally a common elongated hollowframe that is typically hitched to a tractor by a draw bar. The towingframe 2106 is rigidly attached to a front frame 2108 of a four-barlinkage assembly 2110 that is part of the row unit 2104. The four-bar(sometimes referred to as “parallel-bar”) linkage assembly 2110 is aconventional and well known linkage used in agricultural implements topermit the raising and lowering of tools attached thereto.

As the planting row unit 2104 is advanced by the tractor, a pair ofcooperating toothed clearing wheels 2122 clear residue from the soil andthen other portions of the row unit, such as a V-opener disk 2112, partthe cleared soil to form a seed slot, deposit seed in the seed slot andfertilizer adjacent to the seed slot, and close the seed slot bydistributing loosened soil into the seed slot with a pair of closingwheels 2114. According to one example, the closing wheels 2114 areCUVERTINE™ closing wheels sold by the assignee of the presentapplication. The CUVERTINE™ closing wheel is an efficient toothed wheelin-between a spading wheel and a rubber wheel.

A gauge wheel 2116 of the planting row unit 2104 determines the plantingdepth for the seed and the height of introduction of fertilizer, etc.One or more bins 2118 on the planting row unit 2104 carry the chemicalsand seed that are directed into the soil.

The planting row unit 2104 is urged downwardly against the soil by itsown weight. To increase this downward force, or to be able to adjust theforce, a hydraulic or pneumatic actuator 2120 (and/or one or moresprings) is added between the front frame 2108 and the four-bar linkageassembly 2110 to urge the planting row unit 2104 downwardly with acontrollable force. Such a hydraulic actuator 2120 may also be used tolift the row unit off the ground for transport by a heavier, stronger,fixed-height frame that is also used to transport large quantities offertilizer for application via multiple residue-clearing and tillage rowunits. According to one example, the hydraulic actuator 2120 is an RFX™system sold by the assignee of the present application. The RFX™ systemincludes a down-pressure actuator that is a compact, fast actionactuator, and that is remotely controlled. The RFX™ system includes anitrogen pressure-vessel that is integrated with the down-pressureactuator. According to other examples, the hydraulic or pneumaticactuator 2120 may be controlled to adjust the downward force fordifferent soil conditions such as is described in U.S. Pat. Nos.5,709,271, 5,685,245 and 5,479,992.

The planting row unit 2104 further includes a row-clearing unit 2122having a pair of rigid arms 2124 adapted to be rigidly connected to thetowing frame 2106. According to one example, the row-clearing unit 2122is a GFX™ system (i.e., ground effects row cleaner), which is sold bythe assignee of the present application, that is ahydraulically-controlled row cleaner. The GFX™ system is ahydraulically-controlled row cleaner with spring upward pressure andhydraulic down pressure. Furthermore, the GFX™ system is remotelyadjusted.

At the bottom of the row-clearing unit 2122, the pair of cooperatingtoothed clearing wheels 2126 are positioned in front of the V-opener2112 of the planting row unit 2104. The clearing wheels 2126 arearranged for rotation about transverse axes and are driven by engagementwith the underlying soil as the wheels are advanced over the soil. Theillustrative clearing wheels 2126 are a type currently sold by theassignee of the present invention under the trademark TRASHWHEEL™. Theclearing wheels 2126 cooperate to produce a scissors action that breaksup compacted soil and simultaneously clears residue out of the path ofplanting. The clearing wheels 2126 kick residue off to opposite sides,thus clearing a row for planting. To this end, the lower edges aretilted outwardly to assist in clearing the row to be planted. Thisarrangement is particularly well suited for strip tilling, where thestrip cleared for planting is typically only about 10 inches of the30-inch center-to-center spacing between planting rows.

The soil-hardness sensing device 2102 has a first linkage 2130 with anattached blade 2132 and a second linkage 2134 with an attached gaugewheel 2136. According to one example, the linkages are medium FREEFARM™linkages sold by the assignee of the present application. The FREEFARM™linkages are generally modular sets of parallel linkages used fordifferent purposes. Also, according to one example, the soil-hardnesssensing device 2102 is a FORESIGHT AND CFX™ ground hardness sensor thatis sold by the assignee of the present application.

The two linkages 2130, 2134 are parallel to each other and each has adown hydraulic pressure that is controlled independently. Under constanthydraulic pressure, when the soil-hardness sensing device 2102 is movedthrough the field, the blade 2132 penetrates the soil deeper in softsoil and shallower in hard soil. However, the wheel 2136 rides on thesoil surface regardless of the type of soil.

Each linkage 2130, 2134 has a high quality all-stainless steel linearposition sensor 2138, 2140 enclosed in a protecting housing, with acable 2142, 2144 routed to a central processing unit (CPU) 2146, whichincludes a memory device for storing instructions and at least oneprocessor for executing the instructions. When the blade 2132 or thewheel 2136 moves, a corresponding change in position is detected by therespective position sensors 2138, 2140. The two values from the positionsensors 2138, 2140 are outputted as fast as approximately 1,000times/second and are fed as soil-hardness signals to the CPU 2146, whichis a rugged outdoor-rated programmable logic controller that measuresthe difference in the two values in real time.

In the illustrated example, the CPU 2146 is positioned on the plantingrow unit 2104. However, in other embodiments the CPU 2146 may bepositioned remote from the planting row unit 2104, e.g., in a tractorcabin, on a different planting row unit of a side-by-side row unitarrangement, etc. Furthermore the processor and the memory device of theCPU 2146 can be located in the same place, e.g., on the planting rowunit 2104, or in different places, e.g., the processor can be located onthe planting row unit 2104 and the memory device can be located in thetractor cabin.

The CPU 2146 averages the values over a predetermined time period (e.g.,0.25 seconds), executes an algorithm with filtering effects (e.g.,removes conditions in which a rock is hit by the soil-hardness sensingdevice 2102), and provides real-time measurement of the soil hardness.The CPU 2146 optionally receives other user-controllable variables foradjusting/tuning the agricultural system 2100. For example, theuser-controllable variables may include values for different residuelevels, different initial conditions, etc.

Referring to FIG. 37, the agricultural system 2100 receives hydraulicfluid from a hydraulic source, typically located in the tractor, at ahydraulic input pressure P0. The hydraulic fluid is directed to each oneof a plurality of hydraulic control valves V1-V3. The CPU 2146 outputsrespective signals S1-S3 to the respective control valves V1-V3, whichcreate a proportional output/change in the pressure of hydrauliccircuits, virtually instantaneously changing the pressure in real timeas the agricultural system 2100 moves through a field. The pressurechanges are useful, for example, when the agricultural system 2100encounters hardened soil areas in which combines or grain carts havepreviously compacted the soil. The agricultural system 2100 optimizesthe pressure to achieve a desired depth control by applying the rightamount of pressure at the right time.

To achieve the right amount of pressure for each controllable component(e.g., the row-unit actuator 2120, the row-clearing-unit actuator 2122,and the soil-hardness sensing device 2102), the CPU 2146 outputs therespective signals S1-S3 to the associated control valves V1-V3. Forexample, in response to receiving a first signal S1 from the CPU 2146, afirst control valve V1 outputs a proportional first pressure P1 to thehydraulic actuator 2120 (e.g., RFX™ system) for urging the planting rowunit 2104 downwardly. Similarly, in response to receiving a secondsignal S2 from the CPU 2146, a second control valve V2 outputs aproportional second pressure P2 to the row-clearing unit 2122 (e.g.,GFX™ system). The RFX™ system 2120 and the GFX™ system 2122 arecontrolled independently because residue typically exhibits non-linearbehavior. In other words, the independent control of the two systems2120, 2122 is likely to achieve better depth-control results.

A third control valve V3 receives a third signal S3 from the CPU 2145,in response to which the third control valve outputs a proportionalthird pressure P3 to the soil-hardness sensing device 2102 (e.g.,FORESIGHT AND CFX™ system). The control valves V1-V3 return hydraulicfluid to the hydraulic source at a return pressure PR. Respectivetransducers for each of the control valves V1-V3 may be used to verifythat hydraulic output pressures match the desired values. If a hydraulicoutput pressure does not match the desired value, the hydraulic outputpressure is corrected. Furthermore, each of the control valves V1-V3 hasa respective valve response time T1-T3, as discussed in more detailbelow in reference to determining the timing of applying the appropriatepressures P1-P3.

The CPU 2146 further receives an input speed signal SQ indicative of aspeed Q of the agricultural system 2100, which moves typically at about6 miles per hour, i.e., about 8.8 feet per second. As discussed in moredetail below, the speed signal SQ is used to determine the desiredvalues of pressures P1-P3 based on current soil conditions. Furthermore,as discussed in more detail below, the CPU 2146 further outputs twosignals, a sensor signal SCFX to the soil-hardness sensing device 2102and a closing wheel signal SCW to the closing wheel 2114.

The soil-hardness sensing device 2102 is positioned in front of theplanting row unit 2104 at a distance D (which is measured generally froma center line of the blade 2132 to a center line of the V-opener 2112),which can be obtained based on the following formula:Q (speed)=D (distance)/T (time interval)  Equation 1Thus, the distance D is calculated as follows:D=Q*T  Equation 2

If D is a known distance (e.g., the distance between the sensed positionand position where seed-depositing position) and the speed Q is alsoknown, changes in soil conditions can be anticipated in real time priorto the time when each individual tool on the planter row unit 2104arrives at any particular soil-change area. For example, assuming that Qis approximately 8.8 feet per second and T is approximately 0.25seconds, D should be approximately equal to or greater than 2.2 feet. Inother words, the minimum distance for D should be approximately 2.2feet. If D is greater than the minimum value (e.g., D is greater than2.2 feet), the agricultural system 2100 is calibrated to account for theadditional distance. For example, the CPU 2146 will send the respectivesignals S1, S2 to the associated control valves V1, V2 only after apredetermined period of time Tact, as discussed in more detail below.

Pressures P1 and P2 are continually matched with the corresponding soilconditions. For example, P1 and P2 are increased exactly at the timewhen harder soil conditions are encountered directly below the clearingwheels 2126. To properly time the change in pressures P1 and P2correctly, a time variable R refers to the latent processing speed ofCPU 2146 and accounts for the time between (a) receiving an input signalby the CPU 2146, (b) sending output signals S1, S2 by the CPU 2146, and(c) responding to the output signals S2, S2 by the control valves V1, V2with respective outputting pressures P1, P2.

It is noted that each of the control valves V1, V2 has a minimum inputtime Tmin, and that the distance D (e.g., as measured between the centerof the blade 2232 and the center of the V-opener 2212) is directlyproportional to the speed Q multiplied by the minimum input time Tmin ofthe respective control valve V1, V2. It is further noted that atheoretical time Ttheor is directly proportional to the distance Ddivided by the speed Q (i.e., D/Q), and that an actual time Tact isdirectly proportional to the theoretical time Ttheor minus the timevariable R (i.e., Ttheor−R). Based on these conditions, for outputtingpressures P1 and P2, the CPU 146 holds in memory output signals S1 andS2 for a time duration that is equal to the actual time Tact. After theactual time Tact has elapsed, the CPU 146 outputs signals S1 and S2,respectively, to the control valves V1, V2, which respond by outputtingpressures P1, P2. Optionally, signals S1 and S2 are outputted as signalsranging between 0-10 volts.

Referring to FIG. 38, a global positioning system (GPS) provides a GPSsignal indicative of the speed Q to the tractor. Optionally, forexample, the speed Q can be generated from a radar system. The speed Qis inputted to the CPU 2146, along with the soil-hardness signalsreceived from the position sensors 2138, 2140. Based on the speed Q andthe soil-hardness signals, the CPU 2146 outputs signals S1 and S2 to thecontrol valves V1, V2, which output proportional pressures P1 and P2 foradjusting, respectively, the RFX™ system 2120 and the GFX™ system 2122.

Referring to FIGS. 39A-39C, the agricultural system 2100 encountersvarious types of soil-hardness conditions, which, for ease ofunderstanding, will include soft soil conditions and hard soilconditions. The soft soil conditions exemplify typical soil conditions,and the hard soil conditions exemplify compacted soil areas, e.g., areascompacted by tire tracks of tractors or combines.

Referring specifically to FIG. 39A, the agricultural system 2100 ismoving forward at a speed Q over an initial soil area having only softsoil conditions. Based on the soft soil, the blade 2132 penetrates thesoil at a distance X1 lower than the wheel 2136 (which rides on the soilsurface). The distance X1 is the difference between the position sensors2138, 2140. In accordance with the distance X1, which is associated withsoft soil conditions, corresponding pressures P1 and P2 are applied tothe hydraulic actuator 2120 and the row-clearing unit 2122.

Referring specifically to FIG. 39B, the blade 2132 and the wheel 2136(but not the planting row unit 2104) are now moving over a soil area ofhard soil conditions. Because the soil is now much harder than theprevious soil area, the blade 2132 cannot penetrate the soil as much asin the previous soil area. As such, the blade 2132 rises higher relativeto the soil surface and penetrates the soil only at a distance X2 lowerthan the wheel 2136 (which continues to ride on the soil surface). Thedistance X2 is the distance determined by the CPU 2146 based on thecorresponding change in values outputted by the position sensors 2138,2140. However, although the distance X2 (which is associated with hardsoil conditions) is different from the previous distance X1 (which isassociated with soft soil conditions), the corresponding pressures P1and P2 are not changed, yet, because the planting row unit 2104 has notreached the hard-soil area.

Referring specifically to FIG. 39C, the planting row unit 2104 is nowmoving over the hard-soil area, which the blade 2132 and the wheel 136have already passed. At this point in time, and only at this point intime, the pressures P1 and P2 are increased to maintain the desireddepth level. Thus, although the soil-hardness sensing device 2102 hasreached, again, soft soil conditions that allow the blade 2132 topenetrate the soil at the previous distance X1, the pressures P1 and P2are adjusted in accordance with the hard soil conditions.

Referring to FIG. 40A, another exemplary soil-hardness sensing device2202 is attached to a towing frame 2206 which in turn is attached to aplanting row unit 2204 having a V-opener disk 2212, a pair of closingwheels 2214, and a row-unit gauge wheel 2216. The planting row unit 2204further includes a hydraulic actuator 2220 that responds to a pressureP1 and a row-clearing-unit actuator 2222 that responds to a pressure P2.The soil-hardness device 2202 and the planting row unit 2204 aregenerally similar to the soil-hardness device 2102 and the planting rowunit 2104 described above in reference to FIGS. 1-4C, except for anychanges described below.

In this embodiment the soil-hardness device 2202 can be a device that isalready included in the planting row unit 2204, such as a cuttingcoulter running directly in-line with the planter row unit or afertilizer opener positioned off to a side of the planted area. Thus,assuming a side-by-side arrangement of row units, the soil-hardnessdevice can include a fertilizer opener or a no-till cutting coulter infront of every row unit.

The soil-hardness device 2202 includes a blade 2232 and a soil-hardnessgauge wheel 2236. The blade 2232 is attached to a blade arm 2260, andthe soil-hardness gauge wheel 2236 is attached to a wheel arm 2262. Thewheel arm 2262 is biased down by a spring 2264 and pivots relative tothe blade arm 2260. An angular encoder 2266 measures changes in an angleθ between the blade arm 2260 and the wheel arm 2262. The angle θ isdirectly proportional to the depth of the blade 2232 relative to thesoil-hardness gauge wheel 2236.

The angle θ, represented by a signal S4, is sent to a CPU 2246 whichexecutes an algorithm to determine corresponding pressure values for theplanting row unit 2204. A minimum angle θmin is equal to angle θ whenboth the blade 2232 and the soil-hardness gauge wheel 2236 are on thesoil surface, e.g., when passing over very hard soil conditions or aconcrete floor. A depth variable Z indicates a desired blade depth,i.e., blade 2232 penetration into the soil. The angle θ is directlyproportional to the depth variable Z, which has a range between anactual (or current) depth value Zact and a theoretical depth valueZtheor.

By way of comparison, in the soil-hardness device 2202 of the currentembodiment a controllable pressure P3, which is applied to thesoil-hardness device 2202, is varied, but the angle θ between the blade2232 and the soil-hardness gauge wheel 2236 is maintained generallyconstant, with the blade 2232 penetrating the soil at a desired bladedepth Z. In contrast, in the soil-hardness device 2102 described abovein reference to FIGS. 39A-39C the difference between the blade 2132 andthe wheel 2136 is varied (e.g., distances X1 and X2), but the pressureapplied to the soil-hardness device 2102 is maintained generallyconstant.

According to one aspect of the algorithm illustrated in FIG. 40B, theangle θ is measured (2270A) and the actual depth value Zact iscalculated (2270B). Based on the actual depth value Zact and an inputtedtheoretical depth value Ztheor (2270C), a determination is made whetherthe actual depth value Zact is equal to the theoretical depth valueZtheor (2270D):If Zact=Ztheor=>end  Equation 3If the actual depth value Zact is equal to the theoretical depth valueZtheor (i.e., Zact=Ztheor), the algorithm ends (until the next value isreceived) (2270H). Optionally, if angle θ is less than minimum angleθmin (i.e., θ<θmin), algorithm ignores changes because those valuestypically illustrate that the soil-hardness sensing device 2202 has hita rock.

If the actual value of the depth variable Z is greater than thetheoretical value of the depth variable Z (i.e., Zact>Ztheor) (2270E),the controllable pressure P3 that is being applied to the soil-hardnessdevice 2202 is decreased until the actual value of the depth variable Zis equal to the theoretical value of the depth variable Z (i.e.,Zact=Ztheor) (2270F):If Zact>Ztheor=>decrease P3 until Zact=Ztheor  Equation 4If the actual value of the depth variable Z is smaller than thetheoretical value of the depth variable Z (i.e., Zact<Ztheor), then thecontrollable pressure P3 is increased until the actual value of thedepth variable Z is equal to the theoretical value of the depth variableZ (i.e., Zact=Ztheor) (2270G):If Zact<Ztheor=>increase P3 until Zact=Ztheor  Equation 5

Thus, according to this algorithm, the desired depth Z of the blade 2232is maintained constant by varying the pressure P3 in response todetected changes in the angle θ. To vary the pressure P3, a user-definedvariable M (similar to the user-defined variables K and J describedbelow) is increased or decreased to modify an actual value P3act of thepressure P3 until the desired depth variable Z is achieved. As such,assuming that a theoretical value P3theor of the pressure P3 is beingapplied to the blade 2232 when the desired depth Ztheor is achieved, andfurther assuming that P3theor is directly proportional to M * P3act, Mis modified until M * P3act is equal to P3theor (and, consequently, thedesired depth variable Z is achieved). For example, if the depthvariable Z is too small, i.e., the blade 2232 is running too shallowinto the soil (e.g., the blade 2232 is moving through a heavilycompacted soil area), as detected by a change in the angle θ, M isincreased until the actual pressure value P3act is equal to thetheoretical value P3theor. Once the theoretical value P3theor isreached, the increased pressure forces the blade 2232 into the soil atthe desired depth. Furthermore changes to the pressure P1 and thepressure P2 can be effected based on M * P3act being directlyproportional to P1 and P2.

According to another aspect of the algorithm, illustrated in FIG. 40C,if feedback is desired from the row-unit gauge wheel 2216, to verifythat the system is performing as desired (e.g., to verify that theappropriate pressure values are being applied to the planting row unit2204), a weight variable W is set in accordance with a desired weight.In this example, the pressure P1 applied to the hydraulic actuator 2220of the planting row unit 2204 is directly proportional to a user-definedvariable K multiplied by the pressure P3 applied to the soil-hardnessdevice 2202 (i.e., P1 is directly proportional to K * P3).

A signal S5 (illustrated in FIG. 40A), which is directly proportional tothe weight variable W, is outputted by a gauge wheel load sensor 2280(illustrated in FIG. 5A) and averaged over a time period Tgauge. Aftermeasuring the actual weight value Wact (272A) and receiving thetheoretical weight value Wtheor (2272B), a determination is made whetherthe actual weight value Wact is equal to the theoretical weight valueWtheor (2272C):If Wact=Wtheor=>end  (Equation 6)If the actual weight value Wact is equal to the theoretical weight valueWtheor (i.e., Wact=Wtheor), the algorithm ends (2272G) until the nextmeasurement.

If the actual weight value Wact is greater than the theoretical weightvalue Wtheor (i.e., Wact>Wtheor), then the user-defined variable K isdecreased (2272E) until the actual weight value Wact is equal to thetheoretical weight value Wtheor:If Wact>Wtheor=>decrease K  (Equation 7)

If the actual weight value Wact is less than the theoretical weightvalue Wtheor (i.e., Wact<Wtheor), then the user-defined variable K isincreased (2272F) until the actual weight value Wact is equal to thetheoretical weight value Wtheor:If Wact<Wtheor=>increase K  (Equation 8)The user-defined variable K can be set manually by a user orautomatically via a load pin 2282.

Similarly, referring to FIG. 40D, the pressure P2 applied to therow-cleaner unit 2222 can be adjusted by adjusting a user-definedvariable J. Specifically, in this example, the pressure P2 is directlyproportional to the user-defined variable J multiplied by the pressureP3 (i.e. P2 is directly proportional to J * P3). After measuring theactual weight value Wact (2274A) and receiving the theoretical weightvalue Wtheor (2274B), a determination is made whether the actual weightvalue Wact is equal to the theoretical weight value Wtheor (2274C):If Wact=Wtheor=>end  (Equation 9)If the actual weight value Wact is equal to the theoretical weight valueWtheor (i.e., Wact=Wtheor), the algorithm ends (2274G) until the nextmeasurement.

If the actual weight value Wact is greater than the theoretical weightvalue Wtheor (i.e., Wact>Wtheor), then the user-defined variable J isdecreased (274E) until the actual weight value Wact is equal to thetheoretical weight value Wtheor:If Wact>Wtheor=>decrease J  (Equation 10)

If the actual weight value Wact is less than the theoretical weightvalue Wtheor (i.e., Wact<Wtheor), then the user-defined variable J isincreased (2274F) until the actual weight value Wact is equal to thetheoretical weight value Wtheor:If Wact<Wtheor=>increase J  (Equation 11)The user-defined variable J can also be set manually by a user orautomatically via the load pin 282.

Referring to FIGS. 41A and 41B, an agricultural system 2300 includes atractor 2301, two soil-hardness sensing devices 2302A, 2302B, a plantingdevice 2303, and a plurality of planting row units 2304A-2304L, whichare configured in a side-by-side arrangement. In this example, each ofthe planting row units 2304A-2304L has at least one respective controlValve A-L, which is adjustable based on signals received from thesoil-hardness sensing devices 2302A, 2302B.

The tractor 2301 moves at a speed Q, pulling the soil-hardness sensingdevice 2302A, 2302B, the planting device 2303, and the planting rowunits 2304A-2304L along a soil area that includes five soil areas2305A-2305E. Specifically, the soil areas 2305A-2305E includes aright-side outside area 2305A, a right-side wheel area 2305B, a centralarea 2305C, a left-side wheel area 2305D, and a left-side outside area2305E. The right-side wheel area 2305B and the left-side wheel area2305D have soil conditions that are harder than the right-side outsidearea 2305A, the central area 2305C, and the left-side outside area 305E.The harder soil conditions are caused by the wheels of the tractor 2301and/or planting device 2303, which form a compacted path as the tractor301 moves along the soil area. Thus, each of the right-side wheel area2305B and the left-side wheel area 2305D are areas compacted by thewheels of vehicles.

A first soil-hardness sensing device 2302A controls only the plantingrow units 2304E, 2304H that are positioned inside the compacted paths ofthe right-side wheel area 2305B and the left-side wheel area 2305D. Asecond soil-hardness sensing device 2302B controls all the otherplanting row units 2304A-2304D, 2304F-2304G, and 2304I-2304L, i.e., allthe planting row units positioned outside the compact paths of theright-side wheel area 2305B and the left-side wheel area 2305D (andwithin the right-side outside area 305B, the central area 2305C, and theleft-side outside area 2305E). Optionally, any number of soil-hardnesssensing devices and any number of planting row units can be used. Forexample, each of the planting row units 2304A-2304L can have its owndesignated soil-hardness sensing device.

The soil-hardness sensing devices 2302A, 2302B are positioned at adistance D in front of the planting row units 2304A-2304L. Optionally,each of the soil-hardness sensing devices 2302A, 2302B can be positionedat a different distance in front of the planting row units 2304A-2304L.For example, the first soil-hardness sensing device 2302A can bepositioned at a distance X1 in front of the planting row units2304A-2304L and the second soil-hardness sensing device 2302B can bepositioned at a distance X2 in front of the planting row units2304A-2304L. As currently illustrated in FIGS. 41A-41B, the distances X1and X2 are equal to each other (being effectively distance D).Furthermore, the first soil-hardness sensing device 2302A is positionedinside the compacted path of the left-side wheel area 2305D and thesecond soil-hardness sensing device 2302B is positioned inside theleft-side outside area 2305E (i.e., outside the compacted path of thebottom wheel area 305D).

The soil-hardness sensing devices 2302A, 2302B and the attached plantingrow units 2304A-2304L are generally configured to sense soil conditionsand adjust corresponding hydraulic pressures of Valves A-L as describedabove in reference to FIGS. 36-40. The configuration of having multiplesoil-hardness sensing devices 2302A, 2302B increases precision inadjustment of hydraulic pressures, based on current soil conditions,because it accounts for differences between compacted and non-compactedpaths in a field that is being planted. Thus, for example, thesoil-hardness sensing devices 2302A, 2302B provides signals tocorresponding control valves for increasing and/or decreasing hydraulicpressures of the planting row units 2304A-2304L.

The soil-hardness sensing devices discussed above can be remotelycontrolled. For example, the soil-hardness sensing devices 2302A, 2302Bcan be remotely controlled with a handheld radio-frequency remotecontroller. By way of example, the remote controller can be used tomanually increase and/or decrease the hydraulic pressures in one or moreof the soil-hardness sensing devices 2302A, 2302B.

Referring to FIG. 42, the soil-hardness device 2202 illustrated in FIG.40A has been modified to include modular actuators 2220 a-2220 d. Eachof the modular actuators 2220 a-2220 d is identical (or nearlyidentical) to each other as a modular unit that allows the same unit tobe used for movement of different components of the soil-hardness device2202. According to one example, the modular actuators 2220 a-2220 dinclude the hydraulic actuator 2220 described above and illustrated inFIG. 40A or the hydraulic actuator 2120 described above and illustratedin FIG. 36.

Each of the modular actuators 2220 a-2220 d provides controllablepressure for urging the respective components downwardly and/orupwardly, based on the mounting and type of actuator. For example, themodular actuators 2220 a-2220 d can include a double-acting actuator inwhich the controllable pressure can be applied to urge the planting row2104, alternately, both upwards and downwards.

A first modular actuator 2220 a is configured and mounted to apply acontrollable downward force on the entire planting row unit 2204attached to the rear side of the towing frame 2221. A second one of themodular actuators 2220 b is configured and mounted to urge the blade2232 with a controllable force. A third one of the modular actuators2220 c is configured and mounted to urge the row-clearing unit 2222 witha controllable force. A fourth one of the modular actuators 2220 d isconfigured and mounted to urge the closing wheel 2214 with acontrollable force. Thus, for each of the four independently movablecomponents—the planting row unit 2204, the blade 2232, the row-clearingunit 2222, and the closing wheel 2214—the same modular actuator 2220 dis configured to achieve the desired force.

One exemplary benefit of having interchangeable actuators 2220 a-2220 dis that a reduced number of spare parts is required for maintaining thesystem, thus, reducing cost. Another exemplary benefit is that a farmeror operator does not have to learn how to use and/or replace a separateand distinct type of actuator for each movable component. For example,knowing how to replace or maintain the first actuator 2220 a means thatthe farmer knows how to replace or maintain each of the other threeactuators 2220 b-2220 d. As such, the general result of havinginterchangeable actuators is reduced cost and a simpler system.

According to alternative embodiments, any number of modular actuatorscan be adapted for mounting in any agricultural systems. For example,the soil-hardness device 2202 can include two modular actuators of afirst type and two modular actuators of a second type. By way of aspecific example, the first and second actuators 2220 a, 2220 b caninclude a double-acting actuator for applying both upwards and downwardspressure, and the third and fourth actuators 2220 c, 2220 d can includea single-acting actuator for applying either upward or downwardpressure. In other embodiments, the modular actuators are used insystems that lack soil-hardness sensing capabilities.

Referring to FIG. 43, an alternative modular unit 2400 includes amounting bracket 2402 attached to an upper support 2404. A gauge arm2406 is pivotably attached at a proximal end 2407 to a swing arm 2408,which is attached to the upper support 2404. The gauge arm 2406 isattached at a distal end 2409 to a gauge wheel 2410, and the swing arm2408 is further attached to a blade 2432.

The modular unit 2400 includes a modular actuator 2420 that is removablyattached to the upper support 2404 at a fixed end 2422 and to the swingarm 2408 at a movable piston end 2424. The modular actuator 2420 isillustrated in this exemplary embodiment as a pressure-applying devicefor the blade 2432. However, to convert the modular actuator 2420 foruse with a different component (e.g., to apply pressure to therow-clearing unit 2222), the modular actuator 2420 is removed byremoving, for example, an assembly bolt 2426 and/or any other fastenerholding the modular actuator 2420 in place relative to the upper support2404 and the swing arm 2408. Then, the same modular actuator 2420(without the requirement for additional components) can be fastened to adifferent component of the soil-hardness device 2202 (e.g., therow-clearing unit 2222). Thus, removal and/or assembly of the modularactuator 2420 is easily achieved with minimal effort and a small numberof fasteners.

Referring to FIGS. 44A and 44B, according to an alternativeconfiguration, the blade arm 2260 has a distal end 2502 in which aground-hardness sensor 2500 is integrated. The ground-hardness sensor2500 is fixed relative to the blade arm 2260 in a metallic cam 2501 thatincludes an aperture 2504 through which a rotating shaft 2506 protrudes.The rotating shaft 2506 is coupled to the gauge wheel 2236 via the wheelarm 2262. As the soil-hardness sensing device 2202 travels over soil ofvarying conditions (e.g., from hard soil to soft soil), the gauge wheel2236 causes the shaft 2506 to rotate. In turn, the ground-hardnesssensor 2500 detects the rotational movement of the shaft 2506 within theaperture 2504 and provides output indicative of an angular changebetween the supporting arms for the gauge wheel 2236 and the blade 2232.

The ground-hardness sensor 2500 also includes an indicator 2508 that isconfigured to indicate a performance condition. For example, theindicator 2508 is a light-emitting diode (LED) that displays acontinuous green light when the ground-hardness sensor 2500 isfunctioning properly and a flashing red light when a malfunction occurs.

The ground-hardness sensor 2500 is shielded from the environment with acover 2510, which is mounted to the distal end 2502 to enclose withinthe cam 2501. The cover 2510 consists of a translucent or transparentmaterial, such as a clear plastic material, to readily allow visualinspection of the ground-hardness sensor 2500. Thus, one benefit of thecover 2510 is that an operator is not required to remove any parts todetermine whether the ground-hardness sensor 500 is operating properly.

The ground-hardness sensor 2500 is provided in addition to or instead ofthe encoder 266 described above in reference to FIG. 40A. As describedabove, as the shaft 2506 rotates, the ground-hardness sensor 2500measures changes in the angle θ between the blade arm 2260 and the wheelarm 2262 to determine the depth Z of the blade 2232 relative to thesoil-hardness gauge wheel 2236. Then, the angle θ is sent to the CPU2246 for executing the algorithm to determine corresponding pressurevalues for the planting row unit 2204. The angle θ is directlyproportional to the depth of the blade 2232 relative to thesoil-hardness gauge wheel 2236.

The ground-hardness sensor 2500 can be any analog or digital sensor thatis capable of measuring an angular displacement. For example, theground-hardness sensor 2500 can be a linear inductive distance sensor,which is an analog device.

The blade arm 2260 further includes a torsion spring 2512 that engagesthe shaft 2506 to rotationally bias the shaft 2506 toward an equilibriumpoint when the shaft 2506 applies a rotational force. The torsion spring2512 can be attached instead of or in addition to the spring 2264illustrated in FIG. 40A. According to the illustrated example, thetorsion spring 2512 is a compressive, rubber spring with adjustabledown-pressure. Specifically, in this example, the torsion spring 2512 isin the form of an external structure 2512 a in which an internalstructure 2512 b is positioned. The external and internal structures2512 a, 2512 b are generally rectangular and are concentrically alignedalong a central axis. Furthermore, the internal structure 2512 b isoffset at an angle of about 90 degrees relative to the externalstructure 2512 a. When the shaft 2506 rotates in a first direction(e.g., counterclockwise), the internal structure 2512 b moves with theshaft 2506 such that corners of the internal structure 2512 b tend toalign with corners of the external structure 2512 a. Simultaneously, theexternal structure 2512 a applies a second, opposing force (e.g.,clockwise) that counters the first direction and forces the internalstructure 2512 b and the shaft 2506 back towards the equilibrium point.

In addition to applying an opposing force to the rotational force of theshaft 2506, the torsion spring 2512 compresses to dampen the effects ofthe rotational force of the shaft 2506. The compression provides asmoother change in movement for the blade arm 2260, and increases thetorsion spring 2512 resistance to fatigue.

Another benefit of integrating the torsion spring 2512 in the blade arm2260 is that the torsion spring is protected from environmentalconditions, including dirt or mud, that can potentially interfere withthe applied compressive force. Yet another benefit of the torsion spring2512 is that it reduces the number of exposed components, which can be ahazard to human operators.

FIGS. 44C-44G illustrate an application of soil hardness sensing forcontrolling the down pressure on a pair of closing wheels 2551 journaledon a support arm 2553 having an upper end that pivots around ahorizontal axis 2554. A ground gauge wheel 2555 is journaled on asupport arm 2556 having an upper end that pivots around the samehorizontal axis 2554 as the support arm 2553. The ground gauge wheel2555 rolls along the surface of the soil with little variation in itsvertical position relative to the soil surface, because of the wide andsmooth surface area of the wheel 2555. The closing wheels 2551, on theother hand, penetrate into the soil, and thus change their verticalpositions according to the hardness of the soil. The resulting pivotingmovement of the support arm 2553, relative to the more stable positionof the support arm 2556, is thus representative of the soil hardness.This relative pivoting movement of the support arm 2553 is measured byan angular measurement device 2560 coupled to the upper end of thesupport area 2553.

In the illustrative embodiment of FIGS. 44C-44G, the angular measurementdevice 2560 is formed by the combination of (1) a cam 2561 attached to astub shaft 2561 a projecting laterally from the support arm 2553 and (2)an adjacent inductive proximity sensor 2562. As the support arm 2553pivots around the axis 2554, the corresponding angular movement of thecam 2561 is detected by the sensor 2562, which produces an electricaloutput signal that is proportional to the distance between the surfaceof the arm 2561 and the adjacent and of the sensor 2562. That distancevaries as the angular position of the cam 2561 changes with the pivotingmovement of the support arm 2553, and thus the output signal produced bythe sensor 2562 is proportional to the angular position of the supportarm 2853, which in turn is generally proportional to the soil hardness.This signal can be used to regulate the down pressure exerted on theclosing wheels 2551, by the hydraulic actuator 2563, to compensate forvariations in the sensed soil hardness.

FIG. 45 is a schematic diagram of a hydraulic control system for any orall of the hydraulic actuators in the systems described above. Thehydraulic cylinder 2600 is supplied with pressurized hydraulic fluidfrom a source 2601 via a first controllable two-position control valve2602, a restriction 2603 and a check valve 2604. The pressurizedhydraulic fluid supplied to the cylinder 2600 can be returned from thecylinder to a sump 2605 via a second controllable two-position controlvalve 2606, a restriction 2607 and a check valve 2608. Both the controlvalves 2602 and 2606 are normally closed, but can be opened byenergizing respective actuators 2609 and 2610, such as solenoids.Electrical signals for energizing the actuators 2609 and 2610 aresupplied to the respective actuators via lines 2611 and 2612 from acontroller 2613, which in turn may be controlled by a central processor2614. The controller 2613 receives input signals from a plurality ofsensors, which in the example of FIG. 45 includes a pressure transducer2615 coupled to the hydraulic cylinder 2600 via line 2616, and a groundhardness sensor 2617. An accumulator 2618 is also coupled to thehydraulic cylinder 2600, as described in detail above, and a reliefvalve 2619 connects the hydraulic cylinder 2600 to the sump 2605 inresponse to an increase in the pressure in the cylinder 2600 above apredetermined level.

To reduce the energy required from the limited energy source(s)available from the tractor or other propulsion device used to transportthe row units over an agricultural field, the control valves 2602 and2606 are preferably controlled with a pulse width modulation (PWM)control system implemented in the controller 2613. The PWM controlsystem supplies short-duration (e.g., in the range of 50 milliseconds to2 seconds with orifice sizes in the range of 0.020 to 0.2 inch) pulsesto the actuators 2609 and 2610 of the respective control valves 2602 and2606 to open the respective valves for short intervals corresponding tothe widths of the PWM pulses. This significantly reduces the energyrequired to increase or decrease the pressure in the hydraulic cylinder2600. The pressure on the exit side of the control valve is determinedby the widths of the individual pulses and the number of pulses suppliedto the control valves 2602 and 2606. Thus, the pressure applied to thehydraulic cylinder 2622 may be controlled by separately adjusting thetwo control valves 2602 and 2606 by changing the width and/or thefrequency of the electrical pulses supplied to the respective actuators2609 and 2610, by the controller 2613. This avoids the need for aconstant supply current, which is a significant advantage when the onlyavailable power source is located on the tractor or other vehicle thatpropels the soil-engaging implement(s) across a field.

The hydraulic control system of FIG. 45 may be used to control multiplehydraulic cylinders on a single row unit or a group of row units, or maybe replicated for each individual hydraulic cylinder on a row unithaving multiple hydraulic cylinders. For example, in the systemdescribed above having a ground hardness sensor located out in front ofthe clearing wheels, it is desirable to have each hydraulic cylinder onany given row unit separately controlled so that the down pressure oneach tool can be adjusted according to the location of that tool in thedirection of travel. Thus, when the ground hardness sensor detects aregion where the soil is softer because it is wet, the down pressure oneach tool is preferably adjusted to accommodate the softer soil onlyduring the time interval when that particular tool is traversing the wetarea, and this time interval is different for each tool when the toolsare spaced from each other in the direction of travel. In the case of agroup of row units having multiple hydraulic cylinders on each row unit,the same hydraulic control system may control a group of valves havingcommon functions on all the row units in a group.

FIG. 46A is a schematic diagram of a modified hydraulic control systemthat uses a single three-position control valve 2620 in place of the twotwo-position control valves and the two check valves used in the systemof FIG. 45. The centered position of the valve 2620 is the closedposition, which is the normal position of this valve. The valve 2620 hastwo actuators 2620 a and 2620 b, one of which moves the valve to a firstopen position that connects a source 2621 of pressurized hydraulic fluidto a hydraulic cylinder 2622 via restriction 2620 c, and the other ofwhich moves the valve to a second open position that connects thehydraulic cylinder 2622 to a sump 2623. Electrical signals forenergizing the actuators 2620 a and 2620 b are supplied to therespective actuators via lines 2624 and 2625 from a controller 2626,which in turn may be controlled by a central processor 2627. Thecontroller 2626 receives input signals from a pressure transducer 2628coupled to the hydraulic cylinder 2622 via line 2629, and from anauxiliary sensor 2630, such as a ground hardness sensor. An accumulator2631 is coupled to the hydraulic cylinder 2622, and a relief valve 2632connects the hydraulic cylinder 2622 to the sump 2623 in response to anincrease in the pressure in the cylinder 2622 above a predeterminedlevel.

As depicted in FIG. 46B, a PWM control system supplies short-durationpulses P to the actuators 2620 a and 2620 b of the control valve 2620 tomove the valve to either of its two open positions for short intervalscorresponding to the widths of the PWM pulses. This significantlyreduces the energy required to increase or decrease the pressure in thehydraulic cylinder 2622. In FIG. 46B, pulses P1-P3, having a voltagelevel V1, are supplied to the actuator 2620 b when it is desired toincrease the hydraulic pressure supplied to the hydraulic cylinder 2622.The first pulse P1 has a width T1 which is shorter than the width ofpulses P2 and P3, so that the pressure increase is smaller than theincrease that would be produced if P1 had the same width as pulses P2and P3. Pulses P4-P6, which have a voltage level V2, are supplied to theactuator 2620 a when it is desired to decrease the hydraulic pressuresupplied to the hydraulic cylinder 2622. The first pulse P4 has a widththat is shorter than the width T2 of pulses P2 and P3, so that thepressure decrease is smaller than the decrease that would be produced ifP4 had the same width as pulses P5 and P6. When no pulses are suppliedto either of the two actuators 2620 a and 2620 b, as in the “no change”interval in FIG. 46B, the hydraulic pressure remains substantiallyconstant in the hydraulic cylinder 2622.

FIG. 46C illustrates an electrical control system that has a separateelectrical controller 2651, 2652, 2653 . . . 2654 on each of multiplerow units R1, R2, R3 . . . Rn drawn by a single tractor T. Thus, thehydraulic actuators on each row unit can be controlled independently ofthe actuators on the other row units. All the row unit controllers2651-2654 are controlled by a master controller 2650, which may belocated on the tractor or the draw bar, or even on one of the row units.The master controller 2650 sends electrical signals to, and receiveselectrical signals from, each individual row unit in parallel, whichprovides significant advantages, especially when combined with the useof intermittent control signals such as the PWM signals discussed above.For example, the master controller can coordinate changes in pressure inthe multiple row units sequentially, so that only a single row unitdraws power from the source at any given time. In another example, eachrow unit can signal the master controller when power is needed by thatrow unit, and then the master controller can control the supplying ofpower to only those row units requiring adjustment, and during the timeinterval when each row unit requires power for making adjustment. Thisreduces the time required to cycle through the row units to which poweris sequentially supplied. In yet another example, the individual rowunits can send the master controller signals indicating the magnitude ofadjustment required, and the master controller can assign higherpriorities to those row units requiring the largest adjustments, so thatthose row units receive power for making adjustments more quickly thanrow units assigned lower priorities. Or the higher priority row unitscan be provided with power during more cycles than row units havinglower priorities.

Turning now to FIG. 47, a row-clearing unit 3010 is mounted in front ofa planting row unit 3011. A common elongated hollow towing frame 3012(typically hitched to a tractor by a draw bar) is rigidly attached tothe front frame 3013 of a four-bar linkage assembly 3014 that is part ofthe row unit 3011.

As the planting row unit 3011 is advanced by the tractor, a coulterwheel 3015 works the soil and then other portions of the row unit partthe cleared soil to form a seed slot, deposit seed in the seed slot andfertilizer adjacent to the seed slot, and close the seed slot bydistributing loosened soil into the seed slot with a closing wheel 3018.A gauge wheel 3019 determines the planting depth for the seed and theheight of introduction of fertilizer, etc. Bins 3016 and 3017 on the rowunit carry the chemicals and seed which are directed into the soil. Theplanting row unit 3011 is urged downwardly against the soil by its ownweight. If it is desired to have the ability to increase this downwardforce, or to be able to adjust the force, a hydraulic or pneumaticcylinder and/or one or more springs may be added between the front frame3013 and the linkage 3014 to urge the row unit downwardly with acontrollable force. Such a hydraulic cylinder may also be used to liftthe row unit off the ground for transport by a heavier, stronger,fixed-height frame that is also used to transport large quantities offertilizer for application via multiple residue-clearing and tillage rowunits. This hydraulic or pneumatic cylinder may be controlled to adjustthe downward force for different soil conditions such as is described inU.S. Pat. Nos. 5,709,271, 5,685,245 and 5,479,992.

The row-clearing unit 3010 includes an attachment frame that includes apair of rigid arms 3020 and 3021 adapted to be rigidly connected to thetowing frame 3012. In the illustrative embodiment, the arms 3020 and3021 are bolted to opposite sides of the front frame 3013 of the rowunit 3011, which in turn is rigidly attached to the towing frame 3012.An alternative is to attach the row-clearing unit 3010 directly to thetowing frame 3012. At the bottom of the row-clearing unit 3010, a pairof cooperating toothed clearing wheels 3022 and 3023 are positionedupstream of the coulter wheel 3015 of the planting row unit 3011.

The clearing wheels 4022, 4023 are arranged for rotation abouttransverse axes and are driven by the underlying soil as the wheels areadvanced over the soil. The illustrative wheels 4022, 4023 are a typecurrently sold by the assignee of the present invention under thetrademark TRASHWHEEL. The toothed wheels 4022, 4023 cooperate to producea scissors action that breaks up compacted soil and simultaneouslyclears residue out of the path of planting. The wheels 4021 and 4022kick residue off to opposite sides, thus clearing a row for planting. Tothis end, the lower edges are tilted outwardly to assist in clearing therow to be planted. This arrangement is particularly well suited forstrip tilling, where the strip cleared for planting is typically onlyabout 4010 inches of the 4030-inch center-to-center spacing betweenplanting rows.

In FIGS. 47 and 48, the clearing wheels 4022 and 4023 are shown in twodifferent vertical positions. Specifically, the wheels 4022, 4023 are ina lower position in FIG. 1, where the elevation of the soil isdecreasing, than in FIG. 48, where the soil elevation is increasing.

The row-clearing unit 10 is shown in more detail in FIGS. 49-55. The twoframe arms 4020, 4021 are interconnected by an arched crossbar 4024 thatincludes a pair of journals 4025 and 4026 for receiving the leading endsof a pair of laterally spaced support arms 4030 and 4031. The supportarms 4030, 4031 are thus pivotally suspended from the crossbar 4024 ofthe attachment frame, so that the trailing ends of the support arms4030, 4031 can be pivoted in an arc around a horizontal axis 4032extending through the two journals 4025, 4026.

The row-clearing wheels 4022 and 4023 are mounted on the trailing endsof the support arms 4030 and 4031, which are bolted or welded together.As can be seen in FIGS. 50-52, the wheels 4022, 4023 can be raised andlowered by pivoting the support arms 4030, 4031 around the horizontalaxis 4032. The pivoting movement of the support arms 4030, 4031 iscontrolled by a hydraulic cylinder 4070 connected between the fixedcrossbar 4024 and the trailing ends of the support arms 4030, 4031.FIGS. 50-52 show the support arms 4030, 4031, and thus the clearingwheels 4022, 4023, in progressively lower positions. The downwardpressure applied to the support arms 4030, 4031 to urge the clearingwheels 4022, 4023 against the soil is also controlled by the hydrauliccylinder 4070.

The hydraulic cylinder 4070 is shown in more detail in FIGS. 53-55.Pressurized hydraulic fluid from the tractor is supplied by a hose (notshown) to a port 4071 that leads into an annular cavity 4072 surroundinga rod 4073, and then on into an accumulator 4079. After the internalcavities connected to the port 4071 are filled with pressurizedhydraulic fluid, the port is closed by a valve, as will be described inmore detail below. The lower end of the annular cavity 4072 is formed bya shoulder 4074 on the rod 4073, so that the hydraulic pressure exertedby the hydraulic fluid on the surface of the shoulder 4074 urges the rod4073 downwardly (as viewed in FIGS. 53-55), with a force determined bythe pressure of the hydraulic fluid and the area of the exposed surfaceof the shoulder 4074. The hydraulic fluid thus urges the rod 4073 in anadvancing direction (see FIG. 54).

When the rod 4073 is advanced outwardly from the cylinder 4070, the rodpivots the support arms 4030, 4031 downwardly, thereby lowering theclearing wheels 4022, 4023. Conversely, retracting movement of the rod4073 pivots the support arms 4030, 4031 upwardly, thereby raising theclearing wheels 4022, 4023.

The accumulator 4079 includes a diaphragm that divides the interior ofthe accumulator into a hydraulic-fluid chamber 4079 a and a gas-filledchamber 4079 b, e.g., filled with pressurized nitrogen. FIG. 53 showsthe rod 4073 in a position where the diaphragm is not deflected ineither direction, indicating that the pressures exerted on oppositesides of the diaphragm are substantially equal. In FIG. 54, thehydraulic force has advanced the rod 4073 to its most advanced position,which occurs when the resistance offered by the soil to downwardmovement of the clearing wheels 4022, 4023 is reduced (e.g., by softersoil or a depression in the soil).

As can be seen in FIG. 54, advancing movement of the rod 4073 is limitedby the “bottoming out” of a coil spring 4075 located between a flange4076 attached to the inner end of the rod 4073 and a flange 4077attached to the interior of the cylinder 4070. As the rod 4073 isadvanced, the coil spring 4075 is progressively compressed until itreaches its fully compressed condition illustrated in FIG. 54, whichprevents any further advancement of the rod 4073. Advancing movement ofthe rod 4073 also expands the size of the annular cavity 4072 (see FIG.54), which causes the diaphragm 4078 in the accumulator 4079 to deflectto the position illustrated in FIG. 54 and reduce the amount ofhydraulic fluid in the accumulator 4080. When the rod 4073 is in thisadvanced position, the support arms 4030, 4031 and the clearing wheels4022, 4023 are pivoted to their lowermost positions relative to the rowunit 4011.

In FIG. 55, the rod 4073 has been withdrawn to its most retractedposition, which can occur when the clearing wheels 4022, 4023 encountera rock or other obstruction, for example. When the rod 4073 is in thisretracted position, the support arms 4030, 4031 and the clearing wheels4022, 4023 are pivoted to their uppermost positions relative to the rowunit. As can be seen in FIG. 55, retracting movement of the rod 4073 islimited by engagement of a shoulder 4080 on the rod 4073 with a ring4081 on the trailing end of the cylinder 4070. As the rod 4073 isretracted by forces exerted on the clearing wheels 4022, 4023, the coilspring 4075 is progressively expanded, as illustrated in FIG. 55, butstill applies a retracting bias to the rod 4073.

Retracting movement of the rod 4073 virtually eliminates the annularcavity 4072 (see FIG. 55), which causes a portion of the fixed volume ofhydraulic fluid in the cylinder 4070 to flow into the chamber 4079 a ofthe accumulator 4079, causing the diaphragm 4078 to deflect to theposition illustrated in FIG. 55. This deflection of the diaphragm 4078into the chamber 4079 b compresses the gas in that chamber. To enter thechamber 4079 a, the hydraulic fluid must flow through a restriction4080, which limits the rate at which the hydraulic fluid flows into theaccumulator. This controlled rate of flow of the hydraulic fluid has adamping effect on the rate at which the rod 4073 retracts or advances,thereby avoiding sudden large movements of the moving parts of therow-clearing unit.

When the external obstruction causing the row cleaners to rise isremoved from the clearing wheels, the combined effects of thepressurized gas in the accumulator 4079 on the diaphragm 4078 and thepressure of the hydraulic fluid move the rod 4073 to a more advancedposition. This downward force on the clearing wheels 4022, 4023 holdsthem against the soil and prevents uncontrolled bouncing of the wheelsover irregular terrain, but is not so excessive as to leave a trench inthe soil. The downward force applied to the clearing wheels 4022, 4023can be adjusted by changing the pressure of the hydraulic fluid suppliedto the cylinder 4070.

FIG. 56 is a schematic of a hydraulic control system for supplyingpressurized hydraulic fluid to the cylinders 4070 of multiple row units.A source 4100 of pressurized hydraulic fluid, typically located on atractor, supplies hydraulic fluid under pressure to a pressure controlvalve 4101 via supply line 4102 and receives returned fluid through areturn line 4103. The pressure control valve 101 can be set by anelectrical control signal S1 on line 4104 from a controller 4112, todeliver hydraulic fluid to an output line 4105 at a desired pressure.The output line 4105 is connected to a manifold 106 that in turndelivers the pressurized hydraulic fluid to individual feed lines 4107a, 4107 b . . . 4107 n connected to the ports 4071 of the respectivehydraulic cylinders 4070 of the individual row units. The row unitsinclude respective pressure sensors 4108 a, 4108 b . . . 4108 n thatmonitor the forces on the tools to which the respective hydrauliccylinders are coupled, and the sensors produce electrical output signalsthat are fed back to the controller 4112 for use in determining adesired setting for the pressure control valve 4101.

FIG. 57 is a schematic of a modified hydraulic control system thatpermits individual control of the supply of hydraulic fluid to thecylinder of each separate row unit. Portions of this system that arecommon to those of the system of FIG. 56 are identified by the samereference numbers. The difference in this system is that each of theindividual feed lines 4107 a, 4107 b . . . 4107 n leading to the rowunits is provided with a separate pressure control valve 4110 a, 4110 b. . . 4110 n, respectively, that receives its own separate electricalcontrol signal on one of a plurality of output lines 4011 a, 4011 b . .. 4111 c from an electrical controller 4112. This arrangement permitsthe supply of pressurized hydraulic fluid to each row unit to becontrolled by the pressure control valve 110 for that row unit. Theindividual valves 4110 a, 4110 b . . . 4110 n receive pressurizedhydraulic fluid via the manifold 4116 and separate supply lines 4113 a,4113 b . . . 4113 n, and return hydraulic fluid to a sump on the tractorvia a return manifold 4114 connected back to the return line 4103 of thehydraulic system 4100 of the tractor.

One benefit of the control systems of FIGS. 56 and 57 is that asagricultural planters, seeders, fertilizer applicators, tillageequipment and the like become wider with more row units on each frame,often 36 30-inch rows or 54 20-inch rows on a single 90-foot widetoolbar, each row-clearing unit can be controlled independently of everyother row-clearing unit. Thus, the down pressure for each row unit canbe remotely adjustable from the cab of the tractor or other selectedlocation. This permits very efficient operation of a wide planter orother agricultural machine in varying terrain without having to stop tomake manual adjustment to a large number of row units, resulting in areduction in the number of acres planted in a given time period. One ofthe most important factors in obtaining a maximum crop yield is timelyplanting. By permitting remote down force adjustment of eachrow-clearing unit (or group of units), including the ability to quicklyrelease all down force and let the row cleaner quickly rise, e.g., whenapproaching a wet spot in the field, one can significantly increase theplanter productivity or acres planted per day, thereby improving yieldsand reducing costs of production.

On wide planters or other equipment, at times 90 feet wide or more andplanting at 6 mph or more forward speed, one row-clearing unit mustoften rise or fall quickly to clear a rock or plant into an abrupt soildepression. Any resistance to quick movement results in either gougingof the soil or an uncleared portion of the field and reduced yield. Witheach row unit having its own separate control, the clearing wheels andthe rod of the hydraulic cylinder can move quickly and with a nearlyconstant down force.

Although the illustrative embodiments described above utilize clearingwheels as the agricultural tools, it should be understood that theinvention is also applicable to row units that utilize otheragricultural tools, such as fertilizer openers or rollers for firmingloose soil.

In order to dynamically control the hydraulic pressure applied to thesoil-engaging tools in response to varying soil conditions, eachpressure sensor is preferably connected between the ram of eachhydraulic actuator 4019 and the support member for the tool controlledby that ram. One such system is illustrated in FIG. 58, in which atractor hydraulic system 4100 supplies pressurized hydraulic fluid tomultiple row units 4401 a, 4401 b . . . 4401 n. In the illustrativesystem, each row unit includes three hydraulic cylinders 4402, 4403 and4404, one for each of three tool support members 4405, 4406 and 4407,and the hydraulic fluid is supplied to each hydraulic cylinder through aseparate pressure control valve 4408, 4409 or 4410 via a supply manifold4102 and a return manifold 4103. A separate pressure sensor 4411, 4412or 4413 (e.g., a load cell or strain gauge) is connected between the ramof each of the cylinders 4402, 4403 and 4404 and its associated toolsupport member 4405, 4406 or 4407, respectively. The electrical outputsignals from all the pressure sensors 4411-4413 are sent to a controller4420, which generates a separate control signal for each of the pressurecontrol valves 4408, 4409 and 4410.

In FIG. 58, the components of each row unit have been identified by thesame reference numerals used for those same components in the other rowunits, with the addition of the same distinguishing suffixes used forthe row units. For example, in row unit 4401 a, the three hydrauliccylinders have been designated 4402 a, 4403 a and 4404 a. Only three rowunits 4401 a, 401 b . . . 401 n are shown in FIG. 58, but it will beunderstood that any number of row units may be used, and it is commonpractice to have a tractor pull many more than three row units, all ofwhich are coupled to the hydraulic system of the single tractor.

The controller 4420 continuously monitors the electrical output signalsfrom the pressure sensors 4411-4413 and uses those signals to produce aseparate control signal for each of the valves 4408-4410. These signalscontrol the pressure control valves 4408-4410 to maintain desiredhydraulic pressures in the respective hydraulic cylinders 4402-4404 ofall the row units. Consequently, if different row units encounterdifferent soil conditions, those conditions are sensed by the respectivepressure sensors 4115 and the output signals produced by those sensorscause different hydraulic pressures to be supplied to the different rowunits, thereby compensating for the particular soil conditionsencountered by the different row units. For example, if some or all ofthe row units 4401 move from a region of relatively soft soil into aregion of relatively hard soil, the output signals from the pressuresensors 4411-4413 on those row units will increase. These increases aredetected by the controller 4420, which then automatically adjusts thecontrol signals supplied to the corresponding valves to increase thehydraulic pressure supplied to the hydraulic cylinders associated withthose valves.

The system of FIG. 58 is capable of providing independent control of thedown pressure on different tools, such as the clearing wheels and theclosing wheels, on the same row unit. The controller 4420 receives aseparate input signal from the pressure sensor associated with eachseparate cylinder, and produces a separate control signal for eachseparate pressure control valve. Thus, the hydraulic pressure suppliedto each separate hydraulic cylinder may be separately controlled,independently of all the other cylinders, whether on the same row unitor different row units.

The controller 4420 may be programmed to use different algorithms todetermine how the hydraulic pressure supplied to any given cylinder isadjusted in response to changes in the signals from the pressure sensorfor that cylinder. For example, the controller can simply convert thesignal from a given pressure sensor into a proportional signal having alinear relationship with the sensor output signal, to produce a controlsignal that falls within a suitable range for controlling thecorresponding pressure control valve (e.g., within a range of 0-10V).Alternatively, the conversion algorithm can apply a scaling factor orgain to the signal from the sensor as part of the conversion. Filtersmay also be employed in the conversion process, e.g., to ignore sensorsignals above a first threshold value and/or below a second thresholdvalue.

The sensor output signals may also be averaged over a prescribed timeperiod. For example, the signal from each pressure sensor may be sampledat predetermined intervals and averaged over a prescribed time period,so that the control signal supplied to the pressure control valveassociated with that sensor does not change abruptly in response to onlya brief, temporary change in soil conditions. Certain parameters, suchas scaling factors, can be made manually selectable to enable anoperator selection to customize the behavior of one or more row units tosuit personal preferences. Different “mappings” may also be provided toenable an operator to select predetermined sets of variables correlatedto different conditions.

FIGS. 59 and 60 illustrate a load cell 4500 for sensing the pressure ona pair of clearing wheels 4022 and 4023. The load cell 4500 couples therod of the hydraulic cylinder 4070 to the two arms 4030 and 4031 thatcarry the clearing wheels 4022 and 4023, so that the load cell issubjected to the same forces as the clearing wheels. Specifically, theload cell 4500 extends through an annulus 4501 attached to the end ofthe cylinder rod, and the opposite ends of the load cell extend throughclosely fitting apertures in the arms 4030 and 4031 and are securedthereto by a pair of C clips 4502 and 4503. As the forces exerted on theload cell change, the electrical output signal produced by the load cellon its output line 4504 changes in proportion to changes in the exertedforces.

The control system described above may utilize position sensors,pressure transducers, load sensors, biased mechanical switches, etc. todetect varying field conditions, and sends signals to a programmablelogic controller. The controller in turn analyzes and processes thosesignals into a corrected usable signal, to be output to a number ofintegral hydraulic, pneumatic, or electric actuators that controlparameters such as the down force on different parts of each row unit.The information collected in the process is preferably also used for aremote interactive display and controller, or for the development ofsoil condition maps, for use in future field planning, and maintenance.

As the science of agronomy expands, several factors that boost the yieldpotential of various row crops have been identified. Many of thesefactors can be controlled and physically manipulated by means ofmechanical operations on soil and its accompanying residue and/oradditional in-field obstacles such as rocks, waterways, etc. The need tohave real-time control over all implement systems is of criticalimportance as row crop operations move to large platform tools, withsingle operators.

Additionally, the mapping of in-field obstacles has strong potential tosupplement planning for field development and maintenance, such as theremoval of obstacles in the field (e.g., rocks, fence posts, etc.),determining appropriate crop rotation, identifying trouble spots forsoil erosion, identifying areas that may benefit from tiling,determining appropriate tillage practices, and determining applicationrates for fertilizers and pesticides.

Row unit down force can be used to control both the depth of a seedingunit or other agricultural implement, and the compaction of soil from adepth-gauging member such as the gauge wheels on a row crop planter. Twoimportant elements of this process are the ability to ensure that theground-engaging element (e.g., the vee opener blade on a planter rowunit) consistently runs at a uniform depth, and that in the process ofachieving depth, the gauging element(s) does not excessively compact theground. Compacted ground is known to inhibit the germination andemergence of row crop seeds, as well as the lateral root growth of a rowcrop seedling.

Row cleaner down force can be used to control the height and load of afloating row cleaners, which are devices that stretch and deliver rowcrop residue around the path of a seeding implement, or other depthgauging member to ensure that the depth gauging member runs upon aconsistent surface. Running on a consistent surface allows for moreuniform depth of the ground-engaging member. In the case of a seedingmachine, this promotes consistent depth of seed, which is known to boostyield potential.

A controllable down force can be used to regulate both the depth of aground-engaging element of a cutting disc, and compaction caused by anadjacent gauge wheel. As an example, consistent depth of fertilizer isknown to those skilled in the art to promote ideal nutrient uptake in arow crop plant. Consistent depth can also allow for uniform soilcoverage of fertilizer by a furrow-closing device. Uniform coverage canreduce fertilizer loss from surface runoff, and/or loss due tovolatilization of nitrogen, and off gassing.

Closing wheel down force can be used to regulate the depth on afurrow-closing device. Consistent, properly calibrated down pressure anddepth on a furrow closing device on a seeding unit, or other groundengaging tool, can ensure soil coverage over the furrow without causingexcess compaction, or blow-out. This is of particular importance in theplacement of row crop seeds. The seed ideally requires the furrow closerto press soil tight to the seed to promote germination, while allowingthe surface to remain loose, so that the seedling can emerge with littleresistance due to compaction, or crusting.

A depth gauging element actuator is any device that allows for remoteadjustment of the depth-gauging element of a row crop tool. Gaugingdepth is a critical element of almost all row crop tools (seeding units,tillage tools, fertilizer coulters, etc.) In the case of a seeding unit,gauge wheel settings are of primary importance. Uniform depth of theseed is well known to significantly improve yield potential. A realworld example: If the gauge wheels on a seeding unit build up with mud,it is important to adjust the stops on the gauge wheels to correct forthe added increase in radius on the gauge wheels, and maintainvee-opener blade depth.

In one embodiment, a planting row unit is attachable to a towing framefor movement in a forward direction on a field having soil of varyinghardness conditions. The planting row unit includes an opener deviceforward of the towing frame for preparing the soil for receiving atleast one of the fertilizer and the seeds. The opener device includes asoil-hardness sensor for detecting changes in soil-hardness conditionsand an opener blade for maintaining, in response to the changes, asubstantially constant soil-penetration depth Z in the soil independentof the varying hardness conditions. A modular actuator is mounted to theopener device for applying pressure to the opener blade.

The nature of systems of large numbers of sensors and actuators onagricultural implements can be confusing and cumbersome if theperformance of all individual units, and their auxiliary components,cannot be quickly reviewed, and subsequently adjusted in a timelymanner. Row crop production is extremely time and soil-conditionsensitive, and certain operations benefit tremendously from the easingof real-time operator input control, particularly in the case of systemsinstalled on ultra-wide toolbars (over 60 ft.). In many of thesesystems, one operator must monitor and make adjustments to 50 or moreunits. Those units may have 4 or 5 auxiliary systems that also requiremonitoring and adjustment. The necessity to have a comprehensivehigh-speed controller and monitor to assist in regulating all actuatoractivity in a particular system is evident when a single operator mustmonitor and adjust hundreds of components in real-time. Smalleroperators can also realize a significant advantage if methods areproperly employed.

A system for integrated control over all onboard actuators on anagricultural implement is described here. Typical of a row crop tool aretwo primary elements, a ground-engaging component, and a depth-gaugingcomponent. There may be more than one ground-engaging component, ordepth-gauging component, depending on the tool. The positions of thelowest elements of the individual components are necessarily unequal.The lowest element of the ground-engaging component/s is identified bythe extent to which the engaged media (e.g., soil, crop residue) isbeing physically manipulated. The lowest element of the gaugingcomponent regulates the extent to which the ground-engaging componentsmanipulate the engaged media. Regulating the depth on a ground-engagingcomponent is of primary interest.

For measurement and regulation of depth, the chief sensing element ofthis system is a position sensor. This sensor may be linear or angularin nature and, depending on the method, may be either an absolute or arelative displacement sensor. This sensor may also be a laserrangefinder, or ultra-sonic in nature. This measurement is the primaryinput to an onboard programmable controller. The physical devicegenerating this primary input may be used on an auxiliary or add-oncomponent, such as a leading furrow opener having both a ground-engagingmember and a depth-gauging member fitted with a position sensor situatedto measure the relative distance between the ground-engaging membersupport, and the depth-gauging member support. The device may also belocated on the ground-engaging member and depth-gauging member of theprimary tool, such as the vee-opener blades on a seeding unit.Supplementary sensors may be installed both as primary sensing units, aswell as performance correction devices, on the primary tool and onauxiliary tools. For example, on a seeding device, position sensors maybe installed on a leading furrow opener, on a residue-managing device,on the seeding row unit, and on the furrow closer. In many cases, due tocost constraints, operators may choose only one or two position sensorsas their primary signals, with the additional sensor(s) only positivelycontributing to error correction over the entire device. Ideally, allfour inputs are utilized for analyzing a row unit, and auxiliary toolposition, and outputting a signal to all actuators that re-position thetool, or auxiliary components, to allow for maximum performance from thetool and its auxiliary components.

For correction and determination of performance of row crop toolactuators, the chief sensing element is an integrated pressuretransducer. Supplemental performance measurements may include loadsensors (which are pre-installed on many ground-engaging tools) orbiased proximity switches. These sensors may be used to correct errorsthat occur in the processing of the position sensor signal, and toverify that the actuators are performing properly. For example, manyseeding units are equipped with “load pins” on the upper stops of theunits' gauge wheels. Such load pins can generate signals that correlatedirectly to the signals generated by the position sensors.

Integration of mechanical and electrical devices is possible withoutdoor-rated, compact programmable logic controllers. The multi-channelcontroller in this system receives the input signal of the positionsensor of the primary ground-engaging tool, and any additional auxiliarysignals, and then processes those signals to generate a base signal thatis output to the actuators. This signal may be processed using a numberof mathematical methods to output a signal best suited for properresponse from a particular actuator. After the signal is processed, itis checked and corrected using the signals from pressure transducers,load sensors or biased proximity switches. For example, in a seedingunit that is equipped with an actuated furrow opener, an actuatedresidue manager, a row unit down force actuator, and an actuated closingwheel, the primary signal is received from the furrow-opener positionsensor. This signal is supplied to a controller that averages orotherwise mathematically manipulates the signal to produce a clean,consistent signal to each component's actuator. This signal typicallydiffers for each actuator, and different computations are typicallyrequired for each output signal.

Once the signals of all the sensors have been processed and corrected,and the actuators have been activated, it is preferred to be able tovisually inspect the performance of each individual row unit and itsauxiliary components. Also, due to the nature of agricultural fieldwork, it is beneficial to be able to control all elements of the systemfrom a remote location such as a tractor cab. To this end, the systemmay employ a vehicle bus to direct information to an in-cab monitor fromthe individual row controllers, where the information can be processedand viewed in a variety of different configurations. This informationmay also be delivered wirelessly to a remote location to alert anoperator (e.g., via text messaging or e-mail) when errors occur with anactuator or any of its associated sensors. Some operators will choose toemploy all available actuators and all available sensors on all rows,and will want to have direct control row-by-row, in sections, or acrossthe entire toolbar, depending on the operation and the disposition ofthe operator.

The preferred user interface is an interactive in-cab display havingseveral features that allow the operator to quickly review all systemsand adjust the appropriate actuator(s) accordingly. The display mayprovide row-by-row viewing of the functionality of individual tools andauxiliary components, or the functionality may be viewed over integratedsections, or by averages of units over a particular section. Theinterface also alerts the operator when any of the various actuatorsand/or sensors are malfunctioning, and signals which rows or sectionsneed to be checked for repair, or calibration.

There are a large number of mathematical methods by which individualcontrollers process and output signals. Due to the nature of the engagedmedia, the controller must sample the position of a particular tool, orcomponent, and create a meaningful signal to be transmitted to theactuator. When in the field, row crop tools often encounter somerelatively periodic oscillations due to ridges formed from a variety ofpre-plant tools (tillage, fertilizer application, etc.). Additionallythe position sensor will register large spikes as a result ofencountering massive in-field obstacles (e.g., rocks, concrete, fenceposts, etc.). Depending on location, the number of large spikes may bevery frequent. The controllers must be able to register a wide varietyof oscillations. In general, as ground hardness increases, the actuatormust increase down force to push with more force against the hardground. However, a massive, hard object like a rock requires a differentapproach. When encountering a massive object, increasing pressure on theactuators will greatly increase general wear on the row crop tool,potentially causing irreparable damage. Thus, when encountering massiveobjects, the controller preferably recognizes the immovable object and,whenever possible, reduces pressure on the row unit to avoid excessivewear on the tool.

The reading of the signals from the position sensors provides anadditional side benefit. As the data stream feeds into the controller, aforward velocity signal and a GPS coordinate signal may simultaneouslybe gathered from the local CAN. This data collectively can form a soilcondition map of the field, identifying large stones or other obstaclesthat the operator can later efficiently remove by referring to the map.Additionally, when planning for tillage in a particular field, theoperator may use the soil condition map to help identify areas thatrequire more or less tillage.

Rocks, clods, soil type, soil hardness, moisture level and otherenvironmental factors can affect the aperiodic oscillations of anyground-engaging tool sensor signals. The system identifies oscillationsunique to a particular condition, or obstacle, using wave patternrecognition software. This data stream is synchronized with the GPSsignal, and is used to develop a graphical representation of the field,providing a interactive map with GPS coordinate locations of soilcompaction, excessive moisture, in-field obstacles such as rocks, orfence posts that the user may want to remove, or identify otherconditions that, if treated, may boost soil fertility.

This system may employ the input from any number of cameras, eithersection-by-section, or row-by-row. There are a variety of small, robust,weatherproof camera systems available on the market. The implementationof visual surveillance is for two primary purposes: visual verificationof in-field obstacles for use with soil condition maps, and remote rowunit inspection in the case of error signals. When reviewing soilcondition maps generated by the system, it is helpful to visuallyinspect the obstacle, or other condition that is identified by thesystem. Upon encountering a unique signal of interest, the controlleractivates a camera remotely to snap a still shot of the obstacle orcondition of interest, or if the camera is generating video content,that data stream is time-stamped to easily synchronize with the video.The user may then select an obstacle identified by the system as asignal of interest, and visually inspect the ground, to more easilydetermine if it is profitable to remove an obstacle or otherwise treatthe soil.

As toolbars grow in size, the distance from the ground-engaging tool tothe eyes of the operator may be too great for detailed inspection.Further, with the common use of multiple-hose routings for the deliveryof products, and with the integration of high-capacity commodity tanksor hoppers into toolbars, it may be impossible for the operator to seesome rows from the operator's vantage point. If a sensor in the systemsends an error signal, the error may or may not be adversely affectingperformance. The cost of stopping an ultra-wide planter, even for a fewminutes, during the optimal planting window can be significant. If animplement is sending an error message, but upon visual inspection seemsto be functioning adequately, it may prove to be more profitable to keepthe implement moving. In some configurations, having the ability tovisually inspect areas on an implement that has sensors detecting errorscan allow the operator to determine if the problem is critical and needsto be addressed, or if it can wait until the implement consumables aredepleted and is stopped for reloading, or is otherwise down formaintenance.

An additional function of the in-cab display is to assist in controllingthe depth-gauging member of the row crop tool. The ability to remotelycontrol depth may be of use to operators who are working in fields withwidely varying conditions. The ability to slightly raise or lower theground-engaging element of the tool can be critical in someapplications. Additionally, in wet conditions mud build-up on adepth-gauging member may cause erratic and uneven placement of aparticular commodity (e.g., seed, fertilizer), which adversely affectsyield potential.

The system may include a photogate, sonogate, rangefinder or othersensor that directly determines the height of mud buildup on a gaugewheel. This may also be accomplished by using a sensor capable ofdetermining the angular velocity of a wheel. As the radius on the wheelincreases due to mud buildup, the angular velocity changesproportionally, and so may be used to adjust the depth setting toaccount for the additional radius of the gauge wheel. In either case,sensors determine the average displacement between the opener and thegauge wheel. If a change in relative displacement occurs, the systemrecognizes that change, and sends a signal to the gauge wheel actuatorto make the appropriate adjustment, and maintain a set displacement.

FIG. 61 illustrates a complete system of tools that includes (1) asoil-hardness-sensing unit that includes a cutting disc 5001, a gaugewheel 5001 a, a cutting disc position sensor 5002, a cutting discactuator 5003, a cutting disc pressure transducer 5004, a cutting discload sensor/proximity switch 5005; (2) a controllably actuated rowcleaner 5006 that includes a pair of cleaning wheels 5006 a and 5006 b,a row cleaner position sensor 5007, a row cleaner actuator 5008, a rowcleaner pressure transducer 5009, a row cleaner load sensor/proximityswitch 5010; (3) a remotely actuated row unit that includes an actuatorcradle 5011, a row unit position sensor 5012, a row unit actuator 5013,a row unit pressure transducer 5014, a row unit load sensor/proximityswitch 5015; (4) a furrow-opening disc D and an adjacent gauge wheel G;(5) a furrow closing unit 5016 that includes at least one closing wheel5016 a, a furrow closer position sensor 5017, a furrow closer actuator5018, a furrow closer pressure transducer 5019, a furrow closer loadsensor/proximity switch 5020 and a trailing gauge wheel 5021; and (6) arow unit programmable controller 5022.

In FIG. 61, the cutting disc actuator 5003 receives a signal from theposition sensor 5002. This sensor's signal is the initial signal to beprocessed, corrected and then output to the various actuators 5003,5008, 5013 and 5018. Depending on the needs of the operator, some toolsmay be added or removed, but all have the same general configuration:sense position, adjust actuator, and verify or correct signal with loadsensor or proximity switch.

FIG. 62 illustrates an exemplary algorithm for use in the system of FIG.61. In this diagram, the various sensor signals are supplied to andprocessed by the row controller 5022. The signals from the positionsensors, the load sensors, and the pressure transducers of all thecomponents are fed simultaneously into the row unit controller 5022.This may include all the signals from all available sensors, or mayutilize a smaller number of inputs if the demands of the operation donot require more advanced control over a particular operation. After allsensor signals are received, the controller 5022 generates outputsignals that produce any desired changes in the position and/or pressureof all the system actuators. Additionally, if available, the signalsfrom the position sensors may be adjusted by employing the inputs fromthe pressure transducers, or the load sensors associated with theactuators. In this example, every row is controlled individually bymeans of an output signal on a vehicle bus 5024 from the in-cabcontroller/monitor 5025. Here, “Row N” 5023 is the nth row of a largeplatform seeding machine. Each of the N row units has an onboardcontroller 5022 coupled to the vehicle bus 5024 and a battery 5031. Allcomponents may be monitored, and controlled from the in-cab interface.

FIG. 63 is an example of an algorithm similar to the algorithm of FIG.62, but in this case the row cleaner unit has been removed. Despite thelack of a row cleaner, a properly placed position sensor can stillgenerate a usable signal. However, the more inputs, the more potentialphysical malfunctions may occur. In some instances, fewer inputs maylead to a slightly more trouble-free signal generation.

FIG. 64 is another example of a simplified algorithm. In this exampleonly the cutting disc, and the row unit are outfitted with sensors, andactuators. This system requires much less computational power, and onceagain reduces the chance of potential problems that may arise from largenumbers of sensors in a single row unit.

FIG. 65 illustrates a system that provides sectional control over rowunit actuators. In this example, the signals of m row units in each of nsections are fed into a single controller on a master row unit X forthat section. All the other row units in each section are slave unitscontrolled by the controller 5040—in the master row unit. The signalsreceived by the controller 5040 on a master unit are combined togenerate a separate output signal for each of the slave units'actuators. Each section then has its own output that may be monitoredand controlled from the in-cab interface. This sectional control isanother technique to reduce the overall cost of such a system. In manyinstances, field conditions over the width of a small number of rowschange very little. In this case, the operator can still realizesignificant advantages utilizing sectional control.

FIG. 66A shows an in-cab interface when the implement is stationary, andFIG. 66B shows an exemplary display when the implement is moving acrossa field. In this particular example, the implement has five sections ofrow units. The display for each section includes three columns, one foreach of the three different actuators included in each row unit. In thisexample, the actuators are identified as “C” for a coulter, “G” forclearing wheels, and “R” for the row unit, and the bars in therespective columns represent the average performance of all theactuators of each of the three types in the row units in the identifiedsection. The display for each column is a vertical column of smallhorizontal bars. In FIG. 66A, none of the bars is illuminated becausethe implement is stationary. In FIG. 66B, the bars are depicted asilluminated uniformly but, as described in detail below, one of the barsin each column will be illuminated more brightly and with a colordifferent from the other bars in that column, with the vertical positionand color of that bar graphically indicating the average performancelevel of the corresponding tools in the row units in that particularsection.

At the top of each column, a displayed number represents the currentaverage performance of the corresponding is in the row units in thatparticular section, where 100% performance represents sensor signalsthat cause the controller to produce an output signal that does notrequire any changes in the respective actuators for that type of tool inthe row units in that particular section. For example, in Section 1, the98% at the top of column “C” means that the average value of the outputsof the actuators for the coulters in the three row units in Section 1has been within 98% the respective target values for those actuatorsduring the time interval used to compute the average value. The timeinterval used to compute the average values is typically a slidingwindow that is 2 to 5 minutes long, during about 120 to 300 sensorreadings are taken for each actuator.

FIG. 66C depicts an exemplary screenshot 6612 of a modified display on avideo display 6610 in a monitor system 6600 for an agricultural machinesuch as an agricultural seed planter (e.g., a planting unit 10, afertilizer/opener unit, a strip-till cleaner unit, a full-width tillageunit, or any other agricultural machine for which a judgment about howmuch depth penetration of soil is needed or desired). The monitor system6600 includes a controller, such as the controller 112, 2613, 2626,4112, 4420, or the main controller 915, central processor 2614, 2627 ormaster controller 2650, or any other controller or processor describedherein. The controller used to control the displays shown in FIGS.66A-66E is a controller specially programmed with machine-readableinstructions embodied in software and/or firmware to perform the rowmonitoring aspects described in connection with FIGS. 66A-66E.

As described above, the row planting unit 10 includes multiple rowunits, such as 16 in number. Each of the row units has a soil-engagingtool 2202, such as a coulter (e.g., a fertilizer coulter) or V-opener orfurrow-opening disk or coulter 11, 711, 800, 2112, 3015 (sometimescalled CFX™ herein), a row cleaner 2122, 2222 (sometimes called GFX™herein), and/or a closing wheel 2114, 2214 (sometimes called TFX™herein). Each of the row units also includes one or more actuators(typically multiple actuators), such as any combination of a hydraulicactuator 2120, 2220 that actuates the row unit, and one or more modularactuators 2420 which cause the soil-engaging tools 2202, 2104, 3015,2122, 2114 to be urged toward earth (e.g., the soil) according to anactuator signal received from the controller. If there are multiplesoil-engaging tools in any given row unit, then the row unit preferablyhas one actuator for each soil-engaging tool. Thus, if there are foursoil-engaging tools on a row unit, then there are four separateactuators, one for each of the four soil-engaging tools. A“soil-engaging tool” is a tool (or implement) that is configured toengage soil or earth under control of a control system.

In some aspects, the planting row unit itself includes one or more toolsor implements, such as any combination of a coulter, a gauge wheel, ahardness sensor disk or wheel, and the like. Each “tool” is associatedwith at least one actuator that controls the one or more toolsmechanically coupled to that actuator. To avoid confusion, the row unititself (whether it is a planter type, a fertilizer type, a strip-tillcleaner, a full-width tillage type, etc.) can be considered a tool orimplement, such as when it has a gauge wheel or a coulter or the likeattached to it. However, in other aspects, each tool can beindependently actuated by its own respective actuator, and the graphicaluser interfaces shown and described herein enable the operator toseparately monitor at least one measurable parameter for each such toolon the row unit. Thus, when describing a row unit herein as having orincluding a soil-engaging tool, it is more accurate to say that each rowunit has one or more soil-engaging tools “associated with” the row unit.

Each of the row units includes one or more sensors, such as the positionor ground-hardness sensors, pressure sensors, load cells or straingauges described above. Each sensor measures a parameter related to orindicative of the force or pressure exerted on the mechanism associatedwith one of the actuators or the position of that mechanism. Each sensorprovides an electrical signal indicative of the measured parameter tothe controller. The measured parameter can be a force or pressure, or aposition related to a distance traveled by the soil-engaging tool, suchas a depth of soil penetration by the soil-engaging tool. For example,when the sensor is a position sensor, the measured parameter can be aposition related to a distance into the soil penetrated by thesoil-engaging tool, e.g., the position can include an angulardisplacement or distance (e.g., height relative to earth) between thesoil-engaging tool, on one hand, and ground or a reference structure onthe row planting unit 10, on the other hand. When the sensor is apressure sensor, the parameter can be a force or a pressure. Force andpressure are related quantities, so these terms are used interchangeablyherein. Again, there is preferably one sensor for each soil-engagingtool of the row unit. Thus, if there are four soil-engaging tools on arow unit, then there are four separate sensors, one for each of the foursoil-engaging tools. Note that there can be more than one sensor thatmeasures different parameters relating to the same soil-engaging tool.In aspects of the present disclosure, a minimum of one sensor isprovided for each soil-engaging tool in each row, though any number ofsensors can monitor multiple parameters relating to the soil-engagingtool, such as soil hardness of the soil engaged by the tool, soilmoisture, downforce on the tool, load on the tool, vertical position ofthe tool relative to the surface of the soil, angular position of thetool relative to a fixed reference structure, pressure on the tool,geographic location or position of the tool (e.g., GPS coordinates), andthe like.

The video display 6610 is coupled to the controller, which executesmachine-readable instructions stored on one or more non-transitorystorage media. The machine-readable instructions can be implemented asfirmware or software or both and stored on the one or morenon-transitory storage media. The controller causes the video display6610 to display graphical elements thereon, and a conventionaltouch-sensitive interface (not shown) can be coupled to or integral withthe video display 6610 to receive human inputs corresponding toselections of selectable elements displayed on the video display 6610.In the example shown in FIG. 66C, the video display 6610 displays inreal time as the row units are moved along the earth, row monitorgraphical representations 6620, 6630, 6640 that indicate deviations ofmeasured values from target values for different actuators on each ofthe 16 row units. The planting row unit preferably maintains aconsistent soil depth penetration across the field being planted so thatthe seeds are planted a consistent depth into the soil, e.g., 3 inches,depending on the crop being planted. Thus, the measured values can beultimately related to actual soil penetration depths as measured by thesensor(s), and the target values are related to a desired soilpenetration depth as a function of the crop being planted. For example,the measured value can correspond to Z_(ACT), described above inconnection with FIGS. 40A and 40B, and the target value can correspondto Z_(THEOR), described above in connection with FIGS. 40A and 40B.

In the exemplary screen shot in FIG. 66C, there are sixteen row unitsgrouped into three sections, labeled Section 1, Section 2, and Section3, respectively, though any other textual or graphical label can be usedto indicate the different sections. The first Section 1 includes six rowunits, the second Section 2 includes four row units, and the thirdSection 3 includes six row units. The number of row units in each of thesections is merely exemplary, and any number of sections can bepredefined or defined by the operator of the row planting unit 10, wherethe number of sections does not exceed the number of row units.Similarly, any number of row units can be predefined or defined by theoperator of the row planting unit 10, where the number of row units in asection does not exceed the total number of row units in the rowplanting unit 10. No one row unit can be defined to be a member of morethan one section.

The row monitor graphic representations 6620, 6630 and 6640 representactuators on each of the respective row units. In this example, the rowmonitor graphical representation 6620 shows measured parameterdeviations for an actuator acting on the row unit frame in each of thesixteen row units. The row monitor graphical representation 6630 showsmeasured parameter deviations of a fertilizer coulter implement for eachof the sixteen rows. The row monitor graphical representation 6640 showsmeasured parameter deviations of a row cleaner implement for each of thesixteen rows. The screen shot 6612 includes a button 6626, which can beactuated through the touch-sensitive interface to show additional toolsor implements, such as a cleaning wheel implement. As explained above,each row unit includes a hydraulic actuator 2120, 2220 that actuates theplanting row unit 10 as a whole, and the deviation of the measuredparameter from the target parameter is shown for each of the row unitsin the topmost graphical representation 6620.

The screenshot 6612 also includes a target line 6622 that indicates thedesired value of a measured parameter on the row monitor graphicalrepresentation 6620. In this example, the measured parameter deviation(i.e., an indication of whether and how much the measured parameterdeviates from the target parameter) is displayed as an illuminatedhorizontal bar (though any other graphical representation can be used)in real time as the sixteen row units are moved along the earth. Each ofthe sixteen row units is shown as one of sixteen vertical columns 6624-1through 6624-16, each of which graphically resemble a measurement meterfor each of three different actuators in the three windows 520, 6630 and6640.

The target line 6622 bisects each of the vertical meters 6624-1 through6624-16 such that a deviation above the target line 6622 means that toomuch force or pressure is being applied by the corresponding actuator,and a deviation below the target line 6622 means that too little forceor pressure is being applied by that actuator. Alternatively, adeviation above the target line 6622 can mean that too little force orpressure is being applied by the corresponding actuator, and a deviationbelow the target line 6622 can mean that too much force or pressure isbeing applied by that actuator. The target value for each soil-engagingtool can be predetermined and stored in the one or more non-transitorystorage media. Such target values are well known to or readilyascertainable by those of ordinary skill in the art to which the presentdisclosure pertains, and can be dependent upon the type of crop beingplanted by the row planting unit 10.

In the “Planter Down Force Monitor” window 6620 in the display shown inFIG. 66C, the measured parameter deviation for each of the sixteen rowsis shown in a color that represents the extent of the deviations betweenthe measured value and the target value for each planter row unit 10.For example, the color green can be used to indicate that the measuredvalue is within an acceptable range above or below the target value,e.g., a percentage deviation of +/−10% to +/−20% from the target value;the color yellow can be used to indicate that the measured value exceedsbut does not maximally exceed the acceptable range, e.g., a percentagedeviation of +/−20% to +/−40% from the target value; and the colororange can be used to indicate that the measured value maximally exceedsthe acceptable range, e.g., a percentage deviation of +/−40% to +/−80%from the target value. When the measured value exceeds the target valueby more than +/−80%, the color red can be used to indicate a toolmalfunction.

The operator can touch any of the measurement meters corresponding tothe row units to select that row unit or tool for a more detaileddisplay in windows 6650, 6660 and 6670 on the right-hand side of thedisplay screen. In the example shown in FIG. 66C, the operator hasselected the fertilizer coulter in the ninth row by touching the meter6632 in the graphical representation 6630. Thus, the controller causesthe window 6650 to display a graphical portrayal of the soil engagingtool(s) on the ninth row unit. In this example, two soil-engaging toolsare shown in the graphical portrayal 6650, a row cleaner implement(GFX™) and a fertilizer coulter implement (CFX™). Again, fewer or moretools or implements can be displayed by the monitor system, such as aclosing wheel implement (TFX™). The displayed soil-engaging tools areshown in colors corresponding to the colors of the latest measuredvalues for the respective tools for the ninth row unit in the meterwindows 6620, 6630 and 6640. For example, here, the fertilizer coulteris shown in red, indicating a tool failure or malfunction, and the rowcleaner and the row unit down force actuator are shown in green,indicating operation within an acceptable range. A legend 6628, which isnot displayed on the video display 6610, is shown in FIG. 66C to aid thereader in correlating the black-and-white symbol patterns with thedisplayed color.

The display window 6660 displays the latest numerical values measuredfor each of the tools or implements for the selected row or for the rowunit (RFX™) (in this example, the ninth row). In this example, therepresentations are shown as values in psi (pounds per square inch) andcorresponding values in pds (pounds, at the bottom of the implementwhere it engages the soil) for four tools. Here, a closing wheel tool isnot shown on the screenshot 6612, but the operator can use the button6626 to scroll down to see a row monitor graphical representation forthe closing wheel (referred to as “Tfx” in FIG. 66C). One of ten of therow monitor graphical representations 6620, 6630, 6640 may disappearfrom view to make room for the new row monitor graphical representation.The values n1-n4 in the row monitor window 6660 represent the values inpsi measured by the sensors associated with each of the four tools inthe ninth row, and the values n6-n9 represent the values in poundscorresponding to the measurements by the sensors associated with each ofthe four tools in the selected row (here, the ninth row). These valuesn1-n4 and n6-n9 change in real time as the implements are moved alongthe earth by the row planting unit 10. Here, the different tools are asfollows: Cfx refers to a fertilizer coulter or opener tool, which ismonitored in sixteen different rows in the row monitor graphicalrepresentation 6630. Rfx refers to a planter row unit, which ismonitored in sixteen different rows in the row monitor graphicalrepresentation 6640. Gfx refers to a row cleaner tool, which ismonitored in sixteen different rows in the row monitor graphicalrepresentation 6620. Tfx refers to a closing wheel tool, whose rowmonitor graphical representation is not shown in this screenshot 6610.

The screenshot 6612 includes a button 6670 that indicates a row number(here, 9), which corresponds to the row unit selected by the operator asdescribed above. As the row units are being moved along the earth, theoperator can select, via the touch-sensitive interface, the button 6670to change the row unit.

FIG. 66D illustrates an example screenshot 6614 that is displayed inresponse to the operator's selecting the button 6670 shown in FIG. 66C.A number keypad 6672 is shown, and the operator can enter a new row unitnumber using the keypad 6672, and then press the OK button 6674 to causea different row unit (e.g., the first row unit) to be displayed as thegraphical portrayal 6650 and the measured parameters for thesoil-engaging tools for the newly selected row unit to be displayed inthe row monitor window 6660. Alternately, instead of selecting thebutton 6670, the operator can sequentially cycle to the next row byselecting button 6682 or to the previous row by selecting button 6684.The keypad 6672 allows the operator to jump quickly to any desired rownumber, and this feature enhances the user experience as the number ofrow units increases. For example, if the operator is currentlymonitoring row unit number 2, and desires to start monitoring row unitnumber 16, the keypad 6672 allows the operator to quickly beginmonitoring row unit number 16 without having to press a button multipletimes. Or, the operator can simply touch, via the touch-sensitiveinterface relative to the video display 6610, one of the verticalcolumns 6624-1 through 6624-16 for any of the soil-engaging tools tobegin monitoring parameters being monitored by that row unit in the rowmonitor window 6660. By presenting the operator with multiple ways ofeasily selecting any tool in any row, the operator can quickly monitorthose parameters without having to slow down or stop the row plantingunit 10 or focus prolonged attention on the video display 6610, whichwould otherwise lead to a loss of efficiency, unnecessary distraction,or even an accident. For example, if the operator is monitoring row unit2 as the row planting unit 10 is moving along the earth, and suddenlythe column for the row cleaner tool in row number 15 indicates a redcolor indicating a potential tool malfunction, the operator can quicklyeither touch the column (6624-15) for the graphical representation 6640for the row cleaner tool to immediately begin monitoring in real timethe parameter values being measured by the one or more sensorsassociated with the row cleaner tool in that row.

FIG. 66E illustrates an example row diagnostic screen 6616 displayed onthe video display 6610. This screenshot 6616 includes a graphicalrepresentation 6690 of the row planting unit 10 for the selected row(number 9 in this example). The row diagnostic screen 6616 also displaysfour tool parameter monitor windows 6686-1 through 6686-4 and the keypad6672. Each of the tool parameter monitor windows 6686-1 through 6686-4includes an up arrow 6692 u and a down arrow 6692 d, which allows theoperator, via the touch-sensitive interface, to scroll through variousmeasured or calculated parameters associated with the respective tool.For example, the tool parameter monitor window 6686-1 corresponds to afertilizer coulter tool (called Cfx in FIG. 66E), and displays a loadparameter in pounds and a ride quality index (RQI) in percent. The loadcan be measured by one or more of the sensors associated with the tool,and the RQI can be calculated from the measured load. The up and downarrows 6692 u, 6692 d allow the operator to scroll through additionalparameters, shown below the screen 6672 in block 6688. Block 6688 is notactually displayed on the screen 6616 until the operator scrolls throughto them. Rather, for ease of illustration, the block 6688 is shown belowthe screen 6616 and portrays additional parameters that can be monitoredby the operator in the row diagnostic screen 6616. For example, thepressure on the tool in psi can be monitored, the noise in the tractorcabin in dB can be monitored, the power utilized by that row unit or bythat tool can be monitored in amps or watts, and the potential monetarydamage caused by a particular tool malfunction, for example, can becalculated and displayed as a dollar amount. The monetary damage can becalculated as a function of the number of time units a tool hasmalfunctioned, for example, and a predetermined amount of revenuederivable by time unit and stored in the one or more storage mediaaccessed by the row monitor controller.

Three other tools are also shown on the row diagnostic screen 6616.Multiple measured or calculated parameters associated with the rowcleaner tool in row unit number nine is shown or can be accessed byselecting, via the touch-sensitive interface, the up or down arrows 6692u, 6692 d in the tool parameter monitor window 6686-2, multiple measuredor calculated parameters associated with the planter tool in row unitnumber nine is shown or can be accessed by selecting the up or downarrows 6692 u, 6692 d in the tool parameter monitor window 6686-3, andmultiple measured or calculated parameters associated with the closingwheel in row unit number nine is shown or can be accessed by selectingthe up or down arrows 6692 u, 6692 d in the tool parameter monitorwindow 6686-4. Additional tools in row unit number 9 can be accessed byselecting, via the touch-sensitive interface, the left or right arrows6692L, 6692R on the row diagnostic screen 6616. Alternately, the leftand right arrows 6692L, 6692R can be used to move sequentially betweenadjacent row unit numbers. For example, when there are four tools ineach row unit, then all four tool parameter monitor windows 6682-1through 6682-4 can be shown on one screen 6616, allowing the left andright buttons 6692L, 6692R to be used to cycle through the next orprevious row unit. Alternately, the operator can use the keypad 6672 onthe row diagnostic screen 6616 to jump to any row unit number or cycleto an adjacent row unit.

As depicted in FIG. 70, the algorithm described above in connection withFIG. 40B may be modified to produce the values (Z_(ACT)−Z_(THEOR))and/or (Z_(THEOR)−Z_(ACT)) at steps 5270F and 5270G for display at step5279 i, to provide a visual display of the difference between thecurrent actual depth Z_(ACT) and the theoretical depth Z_(THEOR).

FIG. 67 is an example of possible input signals from a sensor associatedwith a tool of or associated with a row unit. Some periodic oscillationsare typical of a real world environment. Ridges are formed in the fieldfrom any number of soil handling operations, and would be apparent fromthe signal received from the position sensors. These small oscillationsare easily removed, and transformed into a smooth, usable signal byaveraging over some time period, and using that averaging as a smoothingoperation. In some cases the implementation of a low pass filter, orother noise cancelling process can be implemented to further smooth thesignal output to the actuator. It is important that any tool smoothly,and consistently follow ground contours. Such an operation requires asmooth consistent signal from the row controller. In FIG.67, ψ(t) is anexample of a real-time signal (e.g., in volts, amps, capacitance, orresistance) being received from the position sensor. Φ(t) is a smoothedsignal to be used a base signal for output to the various actuators.

As has been mentioned previously, massive or immovable objects can beencountered in the field. It is important to detect significant spikesand to remove them from the signal. To that end, one method of sensing aspike is running a differentiation process on the input signal, ψ(t),and determining the slope of a function over a time period. If there isa rapid change in slope over a relatively small period of time, it canbe assumed that the unit has contacted a massive object. In response,the controller can stop taking measurements from the row unit. Afterdetecting the spike, the controller reverts to a recently generatedaverage signal and hold. After a short time, the controller once againbegins sampling the signals from the various row sensors. Eliminatingthese spikes from the input signal greatly reduces the potential forexcess down force on a tool encountering a massive object, which canotherwise greatly reduce the life of a tool.

Another method of eliminating spikes is to average over some time periodand check a phase-shifted multiple of the original signal. As anexample, a “cutoff” point may be 1 or 1.5 standard deviations at anygiven time. The phase shift allows the controller to use a recent signalto eliminate any significant spikes.

FIG. 68 is an exemplary touch-screen display depicting a control panelfor use by an operator to select the type of tool to be monitored on thedisplay.

FIG. 69 is an example of an exemplary interactive map screen. Here,signals of interest are pictorially represented, such as by amost-likely pattern match, on the monitor (e.g., rock, waterway,terrace.). They can be outlined or highlighted in red to be readilyidentified as a potentially troublesome obstacle. Chart 5026 illustratesa possible pictorial representation of tire tracks from a grain cart,combine or tractor tire, or may also represent a pivot track from anirrigation rig. Chart 5027 illustrates an impassable obstacle, like aroadway, or other solid immovable obstacle. Chart 5028 illustrates amassive infield obstacle such as a rock, fencepost or other in-fieldobject. Chart 5029 represents excessive moisture, or waterway in thepath of a particular tool. Chart 5030 is an example of a local anomaly,such as a sand boil, or a rock pile. Chart 5131 is an area of lightresidue. An area of light residue is of interest, because it mayrepresent an area of poor crop performance, or an area prone to erosion.Chart 5032 represents a terrace, or other zone where the implement mayor may not be returning usable consistent signals. Chart 5033 representscontours of variation both in soil density and in moisture content. Suchareas are frequently referred to as management zones. These areas areinteractive, and can be closely analyzed. Selecting the contour in aparticular spot can give some local information about soil type, rockpressure, and moisture levels. To help illustrate, FIG. 69 includes akey showing various in-field conditions graphically. Beside each graphicrepresentation is a possible associated signature signal of a particularin-field obstacle or condition. Signals from position sensors, loadsensors and pressure transducers all have signature signals that reflectthe engaged media. This system identifies the signature signal ofinterest, and produces a graphical representation of the condition onthe map.

Aspects of the present disclosure relate to an agricultural implementrow unit controller (computer), which is integrated row-by-row, or bysection-by-section, for automated control over corresponding actuatorsof a primary ground engaging tool, and its auxiliary components orattachments, or a group of attachments or tools, for example, anycombination of a vee-opener type planter row unit, a fertilizer coulter,a row cleaner, and a closing wheel.

A signal processor operates on input signals from one or more rowunit-mounted sensors, and sends the generated output signal to one ormore row units, and their auxiliary tools actuators, such as, forexample, signals received from position sensors on one or more tools,signals received from pressure transducers on one or more tools, signalsreceived from load sensors of one or more tools, a signal sent to avee-opener type planter row unit down force actuator, a signal sent to arow cleaner actuator, a signal sent to a fertilizer coulter actuator, asignal sent to a closing wheel actuator.

Aspects of the present disclosure also relate to methods of signalprocessing that recognizes signature waveforms unique to a particularfield condition—a “signal of interest.” Input signals are simultaneouslyintegrated and differentiated to identify local maxima, and minima, andtheir associated areas over an experimentally determined time period.Discrete-time optimal control operations (e.g., a Monte Carlo algorithm)can provide additional corrections for signal recognition. This signalincludes information from a position sensor, a laser rangefinder orother sensor designed to measure relative displacement of a groundengaging device, and its depth gauging member, or a combination of suchdevices. This method also identifies errors due to sensor malfunction bynoting that the data stream is absent, or outside of specification, andin some cases may be used to identify mechanical failures of aparticular tool. Signature waveforms unique to a particular conditioncan be used in combination with the forward speed of the tractor, and aGPS signal to create a map that identifies field conditions, andpresents the operator a data stream that can correlate to a map withgraphical representations of a particular conditions.

A signal of interest can be, for example, a spike from a massivein-field obstacle identified by a slope approaching infinity over a timeperiod proportional to the product of an averaged in-field obstaclelength, and an averaged implement velocity; or a signal of interest canbe the signature area, over a predetermined time period, of asemi-regular, semi-repeating signal unique to a particular soilscharacteristics, such as dry bulk density, wet bulk density, porosity,volumetric water content/saturation, particle size distribution,intergranular contact forces, and shear stress.

Another method of signal correction employs the input signals ofexisting implement (tool) sensors, and other supplementary sensors toverify that the primary signal generator is functioning properly, andprovides additional corrected signals that can be superposed into thebase signal to ensure output signals properly affect a given actuator.For example, the signal from a load pin installed on the stops of agauge wheel on a vee-opener type planter row unit, or the signal of apressure transducer installed on a hydraulic actuator can be monitored.These signals correct a primary input signal from a position sensor orother displacement sensor, mounted on an opening coulter, which isleading a planter row unit.)

Another aspect includes a system of cameras, mounted on or near a rowunit, or section of row units, and oriented so that a particular rowunit, or section of row units can be visually inspected remotely. Thissystem has the ability to snap still photographs to be analyzed eitherin real-time, or for reference later to assist in the development of afield maintenance plan.

A graphical user interface (GUI)/computer collects row controllerinformation via a vehicle bus, and simultaneously displays input andoutput information of an agricultural implements row units sensors andunit controllers, and the sensors of the row units auxiliary components.This display shows information on any number of row unit actuatorseither row-by-row or by section averages, such as shown in FIGS.66A-66E. The operator can select a particular tool or tool set, using asimple graphical representation of the tool, or a text description of atool to monitor a particular tools performance, and make judgments onwhether to address errors returned by a local row controller, or if itis more profitable to keep the implement moving (see FIG. 66E), andaddress the error after planter consumables have been depleted and theimplement is stopped. This interface is customizable to allow the userto prioritize toolsets by their individual criteria of importance. Thisinterface also allows for on-the-go changes to the signal processing ofthe individual row controllers. The GUI may also display a photograph ofan erring unit by employing the feed of cameras mounted eitherrow-by-row, or by section, granting the user the ability to visuallyinspect, and make judgment calls on the importance of addressing aparticular error, or if it is more profitable to continue the operationdespite the error. For example, any combination of the following can bedisplayed: the simultaneous display of the overall performance, powerconsumption, system pressure, errors, and profit loss based on thesignals received from the sensors of a row crop planters: actuatedfertilizer coulters, actuated row cleaners, actuated row unit downforce, gauge wheel depth regulators, actuated closing wheels, and alsothe customizable display of additional supplemental, or preexistingsensors.

A user alert system recognizes errors streaming in from the vehicle busand alerts the operator remotely. This alert system uses existing mobileplatforms to send error information to any number of e-mail addresses,or text enabled wireless devices such as tablets, or mobile phones. Thisallows both operators and farm managers to be aware of onboardmalfunctions as they occur. This system also works in tandem with thecamera system to issue a command to a particular camera to generate avisual record of the error.

A system of mapping, created from an incoming data stream from theprimary monitors computer, which presents field condition maps,graphically represented on a GUI either in-cab, or on a remote computer.This map exploits the information collected from the pattern-recognitionalgorithm to make semi-realistic, graphical representations of fieldconditions. These representations are selectable and the user canzoom-in on a particular area to allow for a better understanding of thelevel of profit loss that may be associated with a particular fieldcondition. The map would allow to zoom out to view and entire field, orset of adjacent fields, or zoom in for detailed analysis, such as theidentification, and graphical representation of rocks, waterways,terraces, sand boils, residue levels, tire tracks, grain cart tracks, orany other condition that may require a change to a particular operation,or may require field maintenance.

A system for sensing, using either a photogate, a sonogate, a laserrangefinder or other such device, to directly detect the change inradius on a gauge wheel as it builds with mud and residue, or sheds mudand residue. This signal is processed to be sent to an actuator thatregulates the depth stops on a farm implements depth gauging element. Asan alternative, a sensor that detects angular frequency may be used forexample, in the case of a gauge wheel, as the angular velocitydecreases, it is proportional to an increase in radius, and hence mud ordebris on the wheel. This signal can then be used to determine theproper setting on the stops of the gauge wheel. Additionally, variationsin optimum depth for a agricultural implement may change as theimplement moves through the field, this system allows for on-the-govariations in planting depth to optimize seed placement for a particularset of field conditions.

An actuator that regulates the relative displacement between the lowestmembers of a ground-engaging tool, and that tools depth-gauging member.This actuator would use receive signals from the sensors to ensure agauging member of its associated tool has the ideal displacement fromthe ground-engaging member. This actuator may be hydraulic, or electricin nature, and is robust enough to accommodate the instantaneous forcesassociated with a particular agricultural implement.

It will be evident to those skilled in the art that the invention is notlimited to the details of the foregoing illustrated embodiment and thatthe present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

The invention claimed is:
 1. A monitor system for an agricultural seedplanter having a plurality of row units, the monitor system comprising:a controller; a plurality of row units, each having: a firstsoil-engaging tool; a first actuator causing the first soil-engagingtool to be urged toward earth according to a first actuator signalreceived from the controller, and a first sensor that measures a firstparameter related to or indicative of the first actuator's force orpressure on the first soil-engaging tool and that provides a sensorsignal indicative of the first measured parameter to the controller; avideo display coupled to the controller that is configured to cause thevideo display to display, in real time as the plurality of row units aremoved along the earth, a row monitor graphical representation thatindicates a deviation by the first measured parameter from a firsttarget parameter for the first soil-engaging tool for each respectiveone of the plurality of row units.
 2. The monitor system of claim 1,wherein the measured parameter is a force or a pressure or a positionrelated to a distance traveled by the first soil-engaging tool.
 3. Themonitor system of claim 1, wherein the row monitor graphicalrepresentation includes a plurality of colors, each representing adifferent range of deviations between the measured parameter and thetarget parameter.
 4. The monitor system of claim 3, wherein theplurality of colors include green, which indicates that the firstmeasured parameter is within an acceptable range that includes the firsttarget parameter, yellow, which indicates that the first measuredparameter exceeds but does not maximally exceed the acceptable range,and orange, which indicates that the first measured parameter maximallyexceeds the acceptable range.
 5. The monitor system of claim 3, whereinthe plurality of colors include red, which indicates a malfunctionrelating to the first soil-engaging tool.
 6. The monitor system of claim1, wherein the controller is coupled to one or more non-transitorycomputer-readable media storing thereon a plurality of machine-readableinstructions executed by the controller.
 7. The monitor system of claim1, wherein the controller is further configured to: define one or moresections, each of the one or more sections including one or more rowunits of the plurality of row units such that no one row unit of theplurality of row units is defined to be in more than one of the one ormore sections, and cause the video display to display an indication ofeach of the one or more sections and their corresponding row units. 8.The monitor system of claim 1, wherein the soil-engaging tool is aplanter, a fertilizer coulter, a row cleaner, or a closing wheel.
 9. Themonitor system of claim 1, wherein at least some of the plurality of rowunits includes: a second soil-engaging tool, a second actuator thatcauses the second soil-engaging tool to be urged toward the earthaccording to a second actuator signal received from the controller, anda second sensor that measures a second parameter related to orindicative of the second actuator's force or pressure on the secondsoil-engaging tool and that provides a second sensor signal indicativeof the second measured parameter to the controller, and wherein the rowmonitor graphical representation indicates a deviation by the secondmeasured parameter from a second target parameter for the secondsoil-engaging tool for each respective one of the at least some of theplurality of row units.
 10. The monitor system of claim 9, wherein atleast some of the plurality of row units includes: a third soil-engagingtool, a third actuator that causes the third soil-engaging tool to beurged toward the earth according to a third actuator signal receivedfrom the controller, and a third sensor that measures a third parameterrelated to or indicative of the third actuator's force or pressure onthe third soil-engaging tool and that provides a third sensor signalindicative of the third measured parameter to the controller, andwherein the row monitor graphical representation indicates a deviationby the third measured parameter from a third target parameter for thethird soil-engaging tool for each respective one of the at least some ofthe plurality of row units.
 11. The monitor system of claim 1, whereinthe first, second, and third soil-engaging tools are selected from thegroup consisting of a planter, a fertilizer coulter, a row cleaner, anda closing wheel.
 12. The monitor system of claim 1, further comprising atouch-sensitive interface coupled to or integral with the video display,the controller being configured to: receive, via the touch-sensitiveinterface in real-time as the plurality of row units are moved along theearth, a selection of a graphical representation of a first selected rowunit of the plurality of row units; and responsive to receiving theselection of the graphical representation of the first selected rowunit, the controller causing the video display to display arepresentation of the measured parameter such that the representation ofthe measured parameter and the row monitor graphical representation aredisplayed on the same screen.
 13. The monitor system of claim 12,wherein the controller is further configured to cause to be displayed onthe video display a graphical portrayal of the soil-engaging tool forthe first selected row unit in a color that corresponds to the samecolor used to indicate the deviation by the measured parameter from thetarget parameter for the soil-engaging tool for the first selected rowunit.
 14. The monitor system of claim 13, wherein the color of thegraphical portrayal of the soil-engaging tool for the first selected rowunit changes as the color used to indicate the deviation by the measuredparameter from the target parameter for the soil-engaging tool for thefirst selected row unit changes.
 15. The monitor system of claim 12,wherein the controller is further configured to: cause to be displayedon the video display a button indicating a row number corresponding tothe first selected row unit and a graphical portrayal of thesoil-engaging tool for the first selected row unit; receive, via thetouch-sensitive interface in real-time as the plurality of row units aremoved along the earth, a selection of the button; responsive toreceiving the selection of the button, cause to be displayed on thevideo display a number keypad; receive, via the touch-sensitiveinterface, a row unit number input entered on the number keypadcorresponding to a second selected row unit of the plurality of rowunits; and cause a graphical portrayal of the soil-engaging tool for thesecond selected row unit to be displayed on the video display.
 16. Anagricultural row unit attachable to a towing frame for movement over afield having varying hardness conditions, comprising a planting row unitthat includes an opening device for opening a furrow into which seedscan be planted, a soil-penetrating tool, a gauge wheel mounted forrolling engagement with the soil surface, a sensor coupled to said tooland said gauge wheel for detecting changes in the difference between thevertical positions of said tool and said gauge wheel, and producing anoutput corresponding to said changes, a controllable actuator coupled tosaid tool for applying a downward pressure on said tool, and a controlsystem couple to said actuator and receiving said output of said sensorfor controlling said actuator and thus the downward pressure on saidtool, wherein said soil-penetrating tool is at least one closing wheelfor closing said furrow after seeds have been deposited into saidfurrow.